Half-precast beams and their manufacturing method

Abstract

To provide a half-precast beam and a method for manufacturing it that can reduce the labor involved in setting up and removing formwork, eliminate or reduce the labor required for reinforcing beams, and improve quality. [Solution] The first reinforced precast concrete slab 50A has multiple first reinforcing bars 10A, the first longitudinal bars 11A of which are embedded at intervals in the longitudinal direction of the first precast concrete slab 20A, and the upper end main bars 30 are attached to multiple first upper transverse bars 12A. The second reinforced precast concrete slab 50B has multiple second reinforcing bars 10B, the second longitudinal bars 11B of which are embedded at intervals in the longitudinal direction of the second precast concrete slab 20B, and the lower end main bars 40 are attached to multiple second lower transverse bars 14B. A steel beam 60 is placed in the gap G between the first precast concrete slab 20A and the second precast concrete slab 20B, and a post-cast concrete body 70 is provided to form a half precast beam 100.

Description

Technical Field

[0001] The present invention relates to a half-precast beam and a method for manufacturing the same.

Background Art

[0002] When constructing the upper floor beams and foundation beams made of RC (Reinforced Concrete) in a building (hereinafter referred to as reinforced concrete beams) on site, as a measure to save the labor of installing temporary members and improve the workability, a pair of PCa (Precast) concrete slabs manufactured at a factory or the like are installed with a gap at the beam construction position on site, beam reinforcement is arranged in the gap, and concrete is placed in the gap while using the precast concrete slab as a formwork (side formwork) to construct the reinforced concrete beam. This method may be applied.

[0003] Thus, since a part of the reinforced concrete beam is formed by the precast concrete slab, the reinforced concrete beam constructed by such a construction method can be called a half-precast beam. By applying the half-precast beam, labor can be saved when installing the formwork by using the precast concrete slab as a formwork, and since the precast concrete slab remains as a component of the half-precast beam, labor can also be saved when demolding. Furthermore, the formwork can be included in the cover thickness of the reinforcement, the precast part can be expected to have structural strength, and since the precast concrete slab is factory-made, problems such as concrete janka and cracks that occur when the entire reinforced concrete beam is fabricated on site (constructed on site) can be suppressed, and by ensuring the reinforcement accuracy, the quality can be improved. Also, in the so-called full-precast beam in which the entire reinforced concrete beam is formed by the precast concrete slab, the weight becomes heavy, the transportability decreases, and a large-capacity crane is required during construction, so the construction cost tends to increase. However, by applying the half-precast beam, these problems can be solved.

[0004] Here, Patent Document 1 proposes a method for constructing beams. This method for constructing a reinforced concrete foundation beam involves embedding the main reinforcement bars at the bottom of the beam in the longitudinal direction and the stirrup bars in the short direction, while precast plates are fabricated in advance with one end of the stirrup bars exposed from the side to form a stirrup anchorage section and the other end exposed from the top surface. A pair of precast plates are then placed vertically on a concrete slab for the floor so that the exposed sides of the stirrup anchorage sections face each other. Intermediate beam reinforcement bars are placed in the space formed by the opposing placement of the pair of precast plates to satisfy the required amount of main reinforcement bars and shear reinforcement bars, and concrete is poured into the space to anchor the intermediate beam reinforcement bars and stirrup anchorage sections in the concrete, thereby constructing the foundation beam. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-79695 [Overview of the project] [Problems that the invention aims to solve]

[0006] According to the beam construction method described in Patent Document 1, when constructing reinforced concrete beams, the work related to beam formwork at the construction site can be significantly reduced, thereby achieving labor savings in on-site work.

[0007] Incidentally, while the application of half-precast beams significantly improves labor savings during formwork installation and removal as described above, the effort required for reinforcing the beams within the formwork remains. When using half-precast beams, precast concrete panels that function as formwork may be installed in advance at the left and right positions of the beam reinforcement work space, prior to the reinforcement work. This can reduce the work efficiency and safety of the reinforcement work, and although labor savings can be achieved during formwork installation and removal, there is still room for improvement in terms of overall work efficiency, including the reinforcement work.

[0008] This invention has been made in view of the above problems, and aims to provide a half-precast beam and a method for manufacturing the same, which can reduce the labor required for setting up and removing formwork by using precast concrete slabs that constitute the half-precast beam, eliminate or reduce the labor required for reinforcing the beam, and improve quality. [Means for solving the problem]

[0009] To achieve the above objective, one embodiment of the half-precast beam according to the present invention is: A first reinforced precast concrete slab, comprising a plurality of first reinforcing bars, each having at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward, wherein each of the first longitudinal bars of the plurality of first reinforcing bars is embedded at intervals along the longitudinal direction of the first precast concrete slab, and upper main bars extending along the longitudinal direction are attached below the plurality of first upper transverse bars, The second reinforced concrete slab comprises a plurality of second reinforcing bars, each of which has at least a second longitudinal bar, a second lower transverse bar that bends at the lower end of the second longitudinal bar and extends laterally, and a second lower hook that bends at the end of the second lower transverse bar and extends upward, and each of the second longitudinal bars of the plurality of second reinforcing bars is embedded at intervals in the longitudinal direction of the second precast concrete slab, and lower end main bars that extend in the longitudinal direction are attached above the plurality of second lower transverse bars, The first precast concrete slab and the second precast concrete slab are arranged with a gap between them, a steel beam is installed in the gap, and a post-cast concrete body is provided.

[0010] According to this embodiment, a first reinforced precast concrete slab, in which each of the first longitudinal bars constituting multiple first reinforcing bars is embedded, and a second reinforced precast concrete slab, in which each of the second longitudinal bars constituting multiple second reinforcing bars is embedded, are arranged with a gap between them, a steel beam is placed in the gap, and a post-cast concrete body is provided. As a result, when the first reinforced precast concrete slab and the second reinforced precast concrete slab are installed, the beam reinforcement is automatically arranged. Therefore, the installation and removal of formwork is made easier by using the first and second precast concrete slabs, and the beam reinforcement work is eliminated or made easier. Quality can be ensured because it is manufactured in a factory, and a high-strength and high-rigidity half-precast beam made of SRC (Steel Reinforced Concrete) can be formed.

[0011] Herein, the half-precast beam of this embodiment can be applied to the beams of the upper floors and foundation beams that make up a building. When the beam width is small, it is extremely difficult for workers to enter the pair of precast concrete slabs to perform reinforcement work, and even in the case of foundation beams with a beam depth of about 2m to 3m, it is difficult to perform reinforcement work inside the pair of precast concrete slabs. Therefore, being able to eliminate or reduce the labor required for reinforcement work inside the pair of precast concrete slabs is desirable as it significantly improves the constructability of the foundation beam.

[0012] Furthermore, in another embodiment of the half-precast beam according to the present invention, The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. The first reinforced precast concrete slab and the second reinforced precast concrete slab are arranged with the gap between them, overlapping the first upper horizontal reinforcement and the second upper horizontal reinforcement, and overlapping the first lower horizontal reinforcement and the second lower horizontal reinforcement.

[0013] According to this embodiment, by overlapping the first and second reinforcing bars of both the first reinforced precast concrete slab and the second reinforced precast concrete slab, a half-precast beam can be formed that has high torsional strength and can also ensure ductility by providing a sufficient restraining area.

[0014] Furthermore, in another embodiment of the half-precast beam according to the present invention, The first reinforcing bar has a substantially L-shape and further comprises a first lower hook that bends and extends from the lower end of the first longitudinal bar, and the first upper hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The second reinforcing bar has a substantially L-shape and further comprises a second upper hook that bends and extends from the upper end of the second longitudinal bar, and the second lower hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The first reinforced precast concrete slab and the second reinforced precast concrete slab are arranged with the gap between them, with the first upper horizontal reinforcement and the second upper hooks intersecting, and the second lower horizontal reinforcement and the first lower hooks intersecting.

[0015] According to this embodiment, by intersecting the first and second reinforcing bars of the first reinforced precast concrete slab and the second reinforced precast concrete slab, a half-precast beam can be formed that has high torsional strength and can also ensure ductility by providing a sufficient restraining area.

[0016] Here, "approximately L-shaped" refers to a configuration in which 90-degree hooks, 135-degree hooks, and 180-degree hooks are provided at both ends of an L-shaped reinforcing bar consisting of a first vertical bar and a first upper horizontal bar, or at both ends of an L-shaped reinforcing bar consisting of a second vertical bar and a second lower horizontal bar, respectively.

[0017] Furthermore, other embodiments of the half-precast beam according to the present invention include: Of the upper end main reinforcements attached to the first upper transverse reinforcement and the second upper transverse reinforcement, the upper end main reinforcement positioned at the overlapping position of the first upper transverse reinforcement and the second upper transverse reinforcement is attached below only one of the first upper transverse reinforcement and the second upper transverse reinforcement, and not below the other. Of the lower end main reinforcements attached to the first lower transverse reinforcement and the second lower transverse reinforcement, the lower end main reinforcement positioned at the overlapping position of the first lower transverse reinforcement and the second lower transverse reinforcement is attached above only one of the first lower transverse reinforcement and the second lower transverse reinforcement, and not above the other. The first upper transverse reinforcement and the second upper transverse reinforcement overlap, and the first lower transverse reinforcement and the second lower transverse reinforcement overlap, characterized in that, when these overlap, the multiple upper main reinforcement bars are arranged laterally at equal or approximately equal intervals, and the multiple lower main reinforcement bars are arranged laterally at equal or approximately equal intervals.

[0018] According to this embodiment, of the upper main reinforcement bars attached to the first upper transverse bar and the second upper transverse bar, the upper main reinforcement bar located at the overlap position of the first upper transverse bar and the second upper transverse bar is attached below only one of the first upper transverse bar and the second upper transverse bar, and not below the other. Of the lower main reinforcement bars attached to the first lower transverse bar and the second lower transverse bar, the lower main reinforcement bar located at the overlap position of the first lower transverse bar and the second lower transverse bar is attached above only one of the first lower transverse bar and the second lower transverse bar, and not above the other. When the first upper transverse reinforcement and the second upper transverse reinforcement overlap, and the first lower transverse reinforcement and the second lower transverse reinforcement overlap, multiple upper main reinforcement bars are arranged horizontally at equal or approximately equal intervals, and multiple lower main reinforcement bars are arranged horizontally at equal or approximately equal intervals. This prevents interference between multiple upper main reinforcement bars at the overlapping position of the first and second upper transverse reinforcement bars, and interference between multiple lower main reinforcement bars at the overlapping position of the first and second lower transverse reinforcement bars, while allowing the upper and lower main reinforcement bars to be placed horizontally at equal or approximately equal intervals. Here, "approximately equal intervals" does not mean strictly equal intervals, but includes forms where the intervals differ from place to place due to design considerations, or due to manufacturing errors (reinforcement errors).

[0019] Furthermore, other embodiments of the half-precast beam according to the present invention include: With respect to the first precast concrete slab, at least some of the upper main reinforcement bars of the plurality of upper main reinforcement bars are embedded, The second precast concrete slab is characterized in that at least some of the lower main reinforcement bars among the plurality of lower main reinforcement bars are embedded.

[0020] According to this aspect, by embedding a part of the upper main reinforcement bars (for example, one upper main reinforcement bar) among the plurality of upper main reinforcement bars in the first precast concrete slab and embedding a part of the lower main reinforcement bars (for example, one lower main reinforcement bar) among the plurality of lower main reinforcement bars in the second precast concrete slab, in addition to the first vertical bars and the second vertical bars constituting the first reinforcement bar and the second reinforcement bar, the upper main reinforcement bars and the lower main reinforcement bars are embedded in the first precast concrete slab and the second precast concrete slab, and it is possible to suppress cracking during the transportation and installation of the first precast concrete slab and the second precast concrete slab constituting the precast concrete slab with reinforcement bars before manufacturing the half-precast beam.

[0021] Another aspect of the half-precast beam according to the present invention is The first precast concrete slab includes at least a first vertical slab extending in the vertical direction and a first upper horizontal slab extending in the horizontal direction from the upper end of the first vertical slab. The second precast concrete slab includes at least a second vertical slab extending in the vertical direction and a second lower horizontal slab extending in the horizontal direction from the lower end of the second vertical slab. It is characterized in that a part of the upper main reinforcement bars among the plurality of upper main reinforcement bars is embedded in the first upper horizontal slab, and a part of the lower main reinforcement bars among the plurality of lower main reinforcement bars is embedded in the second lower horizontal slab.

[0022] In this embodiment, the first precast concrete slab comprises a first vertical slab and a first upper horizontal slab extending laterally from the upper end of the first vertical slab, and the second precast concrete slab comprises a second vertical slab and a second lower horizontal slab extending laterally from the lower end of the second vertical slab. In this embodiment, a portion of the upper main reinforcement bars of a plurality of upper main reinforcement bars (for example, one upper main reinforcement bar) is embedded in the first upper horizontal slab, and a portion of the lower main reinforcement bars of a plurality of lower main reinforcement bars (for example, one lower main reinforcement bar) is embedded in the second lower horizontal slab. In addition to the first and second longitudinal bars that constitute the first and second reinforcing bars, the upper and lower main bars are embedded in the first and second precast concrete slabs, which are equipped with the first upper and second lower transverse slabs, respectively. This suppresses cracking during transportation and installation of the first and second precast concrete slabs that constitute the first and second precast concrete slabs with reinforcement bars before the half-precast beams are manufactured.

[0023] Furthermore, other embodiments of the half-precast beam according to the present invention include: The first precast concrete slab comprises a first vertical slab extending in the vertical direction and a first lower horizontal slab extending horizontally from the lower end of the first vertical slab. The second precast concrete slab comprises a second vertical slab extending in the vertical direction and a second lower horizontal slab extending horizontally from the lower end of the second vertical slab. At least a plurality of the lower end main reinforcements are embedded in the second lower horizontal plate, The first lower cross plate and the second lower cross plate are characterized in that their end faces are in contact with each other.

[0024] According to this embodiment, the first precast concrete slab comprises a first vertical slab and a first lower horizontal slab extending laterally from the lower end of the first vertical slab, and the second precast concrete slab comprises a second vertical slab and a second lower horizontal slab extending laterally from the lower end of the second vertical slab, and in a configuration in which the end faces of the first lower horizontal slab and the second lower horizontal slab of the first reinforced precast concrete slab and the second reinforced precast concrete slab are in contact with each other and a gap is formed above them, at least multiple lower main reinforcements are embedded in the second lower horizontal slab, so that in addition to the second vertical reinforcements that constitute the second reinforcing bars, the lower main reinforcements are embedded in the second precast concrete slab that comprises the second lower horizontal slab, and cracking during transportation and installation of the second precast concrete slab that constitutes the second reinforced precast concrete slab before the half-precast beam is manufactured.

[0025] Furthermore, other embodiments of the half-precast beam according to the present invention include: The first precast concrete slab comprises a first vertical slab extending in the vertical direction, The second precast concrete slab comprises a second vertical slab extending in the vertical direction, A first upper recess and a first lower recess are provided on the inner side of the upper and lower ends of the first vertical plate, respectively. The second vertical plate is characterized by having a second upper recess and a second lower recess on the inner side of the upper and lower ends, respectively.

[0026] According to this embodiment, the first vertical plate of the first precast concrete slab has a first upper recess and a first lower recess on the inside of its upper and lower ends, respectively, and the second vertical plate of the second precast concrete slab has a second upper recess and a second lower recess on the inside of its upper and lower ends, respectively. As a result, the upper and lower main reinforcement bars adjacent to each upper and lower recess are separated laterally from the first and second vertical plates, respectively. This allows the concrete used to form the post-cast concrete body to sufficiently wrap around the upper and lower main reinforcement bars adjacent to the first and second vertical plates, and enables the upper and lower main reinforcement bars placed at the ends to be embedded without gaps inside the post-cast concrete body.

[0027] Furthermore, other embodiments of the half-precast beam according to the present invention include: The device comprises a plurality of first reinforcing bars, each comprising at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward. It comprises a plurality of separate first reinforcing bars, each comprising at least a separate first longitudinal bar and a separate first upper transverse bar that bends at the upper end of the separate first longitudinal bar and extends laterally. Each of the aforementioned separate first reinforcing bars is embedded at intervals in the longitudinal direction of the first precast concrete slab. For each of the aforementioned separate first reinforcing bars, the corresponding first upper transverse bar of the first reinforcing bar is arranged to overlap and then tied or welded together. A precast concrete slab with third reinforcement bars, wherein the upper main reinforcement bars extending in the longitudinal direction are attached below a plurality of the first upper transverse reinforcements, The device comprises a plurality of second reinforcing bars, each having at least a second longitudinal bar, a second lower transverse bar that bends at the lower end of the second longitudinal bar and extends laterally, and a second lower hook that bends at the end of the second lower transverse bar and extends upward. It comprises a plurality of separate second reinforcing bars, each comprising at least a separate second longitudinal bar and a separate second lower transverse bar that bends at the lower end of the separate second longitudinal bar and extends laterally. Each of the aforementioned separate second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab. The second lower transverse bar of the corresponding second reinforcing bar is arranged to overlap with the second lower transverse bar of each of the aforementioned separate second reinforcing bars, and is then tied or welded together. It comprises a precast concrete slab with a fourth reinforced concrete slab, to which the longitudinally extending lower end main reinforcement is attached above a plurality of the aforementioned second lower transverse reinforcements, The first precast concrete slab and the second precast concrete slab are arranged with a gap between them, a steel beam is installed in the gap, and a post-cast concrete body is provided.

[0028] In this embodiment, each of the separate first longitudinal bars forming a plurality of separate first reinforcing bars is embedded at intervals in the longitudinal direction of the first precast concrete slab, and the corresponding first upper transverse bar of the first reinforcing bar is arranged to overlap with the separate first upper transverse bar of each separate first reinforcing bar and tied together, and the upper main bars are attached below the plurality of first upper transverse bars to form the third reinforced precast concrete slab. Each of the separate second longitudinal bars forming a plurality of separate second reinforcing bars is embedded at intervals in the longitudinal direction of the second precast concrete slab, and the corresponding second lower transverse bar of the second reinforcing bar is arranged to overlap with the separate second lower transverse bar of each separate second reinforcing bar and tied together, and the lower main bars are attached above the plurality of second lower transverse bars. With the reinforcement bars attached to form the fourth reinforced precast concrete slab, the third and fourth precast concrete slabs are placed with a gap between them, a steel beam is placed in the gap, and a post-cast concrete body is provided. As a result, when the third and fourth reinforced precast concrete slabs are installed, the beam reinforcement is automatically arranged. Therefore, the third and fourth precast concrete slabs reduce the labor required for formwork installation and removal, eliminate or reduce the labor required for beam reinforcement, ensure quality because they are factory-made, and form a high-strength and high-rigidity half-precast beam made of SRC.

[0029] Furthermore, in another embodiment of the half-precast beam according to the present invention, The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. The third reinforced precast concrete slab and the fourth reinforced precast concrete slab are arranged with the gap between them, overlapping the first upper horizontal reinforcement and the second upper horizontal reinforcement, and overlapping the first lower horizontal reinforcement and the second lower horizontal reinforcement.

[0030] According to this embodiment, by overlapping the first and second reinforcing bars of both the third reinforced concrete slab and the fourth reinforced concrete slab, a half-precast beam can be formed that has high torsional strength and can also ensure ductility by providing a sufficient restraining area.

[0031] Furthermore, in another embodiment of the half-precast beam according to the present invention, The first longitudinal reinforcement has a substantially L-shape, further comprising a first lower hook that bends and extends from the lower end of the first longitudinal reinforcement, and the first upper hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The second longitudinal reinforcement has a substantially L-shape, further comprising a second upper hook that bends and extends from the upper end of the second longitudinal reinforcement, and the second lower hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The third reinforced precast concrete slab and the fourth reinforced precast concrete slab are arranged with the gap between them, with the first upper horizontal reinforcement and the second upper hook intersecting, and the second lower horizontal reinforcement and the first lower hook intersecting.

[0032] According to this embodiment, by intersecting the first and second reinforcing bars of the third reinforced precast concrete slab and the fourth reinforced precast concrete slab, a half-precast beam can be formed that has high torsional strength and can also ensure ductility by providing a sufficient restraining area.

[0033] Furthermore, other embodiments of the half-precast beam according to the present invention include: In the longitudinal direction, a first reinforcing bar is arranged between the first reinforcing bars that are tied or welded to the other first reinforcing bar, and the other first reinforcing bar is not present between them. In the longitudinal direction, the second reinforcing bar is arranged between the second reinforcing bars that are tied or welded to the other second reinforcing bar, in which there is no counterpart second reinforcing bar.

[0034] According to this embodiment, first and second reinforcing bars are arranged between first reinforcing bars that are tied to a separate first reinforcing bar, or between second reinforcing bars that are tied to a separate second reinforcing bar, without the presence of the other separate first or second reinforcing bars. In other words, by arranging first and second reinforcing bars that are not connected to a separate first or second reinforcing bar, in addition to first and second reinforcing bars that are connected to a separate first or second reinforcing bar, it is possible to arrange a number of first and second reinforcing bars that can achieve the desired shear reinforcement effect, without depending on the number of separate first and second reinforcing bars. Here, the first and second reinforcing bars that are not connected to a separate first or second reinforcing bar are all connected together with the first and second reinforcing bars that are connected to a separate first or second reinforcing bar, via upper and lower main bars.

[0035] Furthermore, other embodiments of the half-precast beam according to the present invention include: Multiple upper main reinforcement bars are provided in multiple stages, and each stage contains multiple upper main reinforcement bars. The lower main reinforcement bars are provided in multiple stages, and each stage contains multiple lower main reinforcement bars.

[0036] According to this embodiment, since multiple upper main reinforcement bars are provided in multiple stages, with multiple upper main reinforcement bars included in each stage, and multiple lower main reinforcement bars are provided in multiple stages, a half-precast beam with even greater strength can be formed.

[0037] Furthermore, other embodiments of the half-precast beam according to the present invention include: The first auxiliary reinforcement, which prevents the sagging or swaying of the first upper transverse reinforcement to which the upper main reinforcement is attached, is arranged so as to straddle the first upper transverse reinforcement and the first vertical reinforcement. The second auxiliary reinforcement, which prevents the sagging or swaying of the second lower horizontal reinforcement to which the lower main reinforcement is attached, is characterized in that it is arranged so as to straddle the second lower horizontal reinforcement and the second vertical reinforcement.

[0038] According to this embodiment, a first auxiliary reinforcement is provided to prevent the first upper horizontal reinforcement, to which the upper main reinforcement is attached, from sagging or swaying when suspended, and a second auxiliary reinforcement is provided to prevent the second lower horizontal reinforcement, to which the lower main reinforcement is attached, from sagging or swaying when suspended, thereby effectively preventing the first upper horizontal reinforcement and the second lower horizontal reinforcement from sagging or swaying when suspended, caused by the weight of the upper and lower main reinforcement.

[0039] Furthermore, other embodiments of the half-precast beam according to the present invention include: Among the plurality of first and second reinforcing bars arranged in the longitudinal direction, some of the first and second reinforcing bars have relatively large cross-sectional diameters, and these large-diameter reinforcing bars prevent both the first upper transverse bar and the second lower transverse bar from sagging or swaying.

[0040] According to this embodiment, some of the first reinforcing bars among the plurality of first reinforcing bars, and some of the second reinforcing bars among the plurality of second reinforcing bars, are first and second reinforcing bars with relatively large cross-sectional diameters. By preventing both the first upper transverse bar and the second lower transverse bar from sagging or swaying when suspended, the first upper transverse bar and the second lower transverse bar caused by the weight of the upper and lower main bars can be effectively prevented by some of the first and second reinforcing bars without the use of auxiliary bars.

[0041] Furthermore, other embodiments of the half-precast beam according to the present invention include: One of the first upper hook and the second upper hook is a 90-degree hook or a 135-degree hook, and the other is a 135-degree hook. The first lower hook and the second lower hook are characterized in that one of them is a 90-degree hook or a 135-degree hook, and the other is a 135-degree hook.

[0042] According to this embodiment, by having the mutually engaging first upper hook and second upper hook, and the first lower hook and second lower hook, all be combinations of 135-degree hooks and 90-degree hooks, or combinations of 135-degree hooks and 135-degree hooks, the stress transmission between the first and second reinforcing bars of the first reinforced precast concrete slab and the second reinforced precast concrete slab can be improved. More specifically, when a tensile force applied to one reinforcing bar surrounding the upper or lower main reinforcement transmits stress to the reinforcing bar on the opposite side, the upper and lower main reinforcement bars between them act as dowels, resulting in higher stress transmission compared to the case where the upper and lower main reinforcement bars are not present.

[0043] Furthermore, one embodiment of the method for manufacturing a half-precast beam according to the present invention is: A first reinforced precast concrete slab, comprising a plurality of first reinforcing bars, each having at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward, wherein each of the first longitudinal bars of the plurality of first reinforcing bars is embedded at intervals along the longitudinal direction of the first precast concrete slab, and upper main bars extending along the longitudinal direction are attached below the plurality of first upper transverse bars, A precast concrete slab with second reinforcing bars is prepared, and a steel beam is prepared, wherein each of the second vertical bars of a plurality of second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a second lower hook is attached above the plurality of second lower horizontal bars, each comprising at least a second vertical bar, a second lower horizontal bar that bends at the lower end of the second vertical bar and extends laterally, and a second lower hook that bends at the end of the second lower horizontal bar and extends upward, and each of the second vertical bars of the plurality of second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main bar that extends along the longitudinal direction is attached above the plurality of second lower horizontal bars. Position the first reinforced precast concrete slab, arrange the steel beam inside the first reinforced precast concrete slab, move the second reinforced precast concrete slab to position it with a gap between the first and second precast concrete slabs, and move and position the steel beam in the center of the gap. The method is characterized by producing a half-precast beam by pouring concrete into the aforementioned gap to form a post-cast concrete body.

[0044] According to this embodiment, by positioning a first reinforced precast concrete slab in which each of the multiple first reinforcing bars, each of the first longitudinal bars constituting the first reinforcement bars, is embedded, arranging a steel beam inside the first reinforced precast concrete slab, moving a second reinforced precast concrete slab in which each of the multiple second reinforcing bars, each of the second longitudinal bars constituting the second reinforcement bars, positioning it with a gap between the first and second precast concrete slabs, and moving and positioning the steel beam at the center of the gap, the reinforcement of the beam can be automatically arranged when the first and second reinforced precast concrete slabs are positioned, thereby eliminating or suppressing separate reinforcement work for the beam. Furthermore, by using the first and second precast concrete slabs as side frames and pouring concrete into the gap between them to form a post-cast concrete body, the labor required for formwork installation and removal can be reduced.

[0045] Furthermore, in another embodiment of the method for manufacturing a half-precast beam according to the present invention, The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. Of the upper end main reinforcements attached to the first upper transverse reinforcement and the second upper transverse reinforcement, the upper end main reinforcement positioned at the overlapping position of the first upper transverse reinforcement and the second upper transverse reinforcement is attached below only one of the first upper transverse reinforcement and the second upper transverse reinforcement, and not below the other. Of the lower end main reinforcements attached to the first lower transverse reinforcement and the second lower transverse reinforcement, the lower end main reinforcement positioned at the overlapping position of the first lower transverse reinforcement and the second lower transverse reinforcement is attached above only one of the first lower transverse reinforcement and the second lower transverse reinforcement, and not above the other. The first upper transverse reinforcement and the second upper transverse reinforcement are overlapped, and the first lower transverse reinforcement and the second lower transverse reinforcement are overlapped, thereby arranging multiple upper main reinforcement bars at equal or approximately equal intervals in the lateral direction, and arranging multiple lower main reinforcement bars at equal or approximately equal intervals in the lateral direction.

[0046] According to this embodiment, of the upper main reinforcements attached to the first upper transverse reinforcement of the first reinforcement bar of the first reinforced concrete slab with first reinforcement bars and the second upper transverse reinforcement of the second reinforcement bar of the second reinforced concrete slab with second reinforcement bars, the upper main reinforcement located at the overlap position of the first upper transverse reinforcement bar and the second upper transverse reinforcement bar is attached below only one of the first upper transverse reinforcement bar and the second upper transverse reinforcement bar, and not below the other, and of the lower main reinforcements attached to the first lower transverse reinforcement bar of the first reinforcement bar and the second lower transverse reinforcement bar of the second reinforcement bar, the lower main reinforcement located at the overlap position of the first lower transverse reinforcement bar and the second lower transverse reinforcement bar is the first The reinforcement bars are installed above only one of the lower transverse bars and the second lower transverse bar, and not above the other. When the first upper transverse bar and the second upper transverse bar overlap, and the first lower transverse bar and the second lower transverse bar overlap, multiple upper main reinforcement bars are arranged horizontally at equal or approximately equal intervals, and multiple lower main reinforcement bars are arranged horizontally at equal or approximately equal intervals. This prevents interference between multiple upper main reinforcement bars at the overlapping position of the first and second upper transverse bars, and interference between multiple lower main reinforcement bars at the overlapping position of the first and second lower transverse bars, while allowing the upper and lower main reinforcement bars to be arranged horizontally at equal or approximately equal intervals.

[0047] Furthermore, another aspect of the method for manufacturing a half-precast beam according to the present invention is: The first precast concrete slab comprises at least a first vertical slab extending in the vertical direction and a first lower horizontal slab extending horizontally from the lower end of the first vertical slab. The second precast concrete slab comprises at least a second vertical slab extending in the vertical direction and a second lower horizontal slab extending horizontally from the lower end of the second vertical slab. Multiple lower end main reinforcements are embedded in the second lower horizontal plate. By bringing the end faces of the first lower horizontal plate and the second lower horizontal plate into contact with each other, the first vertical plate and the second vertical plate, along with the first lower horizontal plate and the second lower horizontal plate, form a U-shaped formwork with a cross-sectional shape perpendicular to the longitudinal direction that opens upward. The method is characterized by pouring concrete into the formwork to form the post-cast concrete body.

[0048] According to this embodiment, the first precast concrete slab comprises a first vertical slab and a first lower horizontal slab extending laterally from its lower end, and the second precast concrete slab comprises a second vertical slab and a second lower horizontal slab extending laterally from its lower end. By bringing the end faces of the first and second lower horizontal slabs of the first and second reinforced precast concrete slabs together, a U-shaped formwork with a cross-sectional shape perpendicular to the longitudinal direction that opens upward is formed. As a result, the entire formwork, including the side frame and bottom frame, is formed by the first and second reinforced precast concrete slabs. This eliminates the need to separately install formwork (such as its components, the bottom frame) and the need to demold the formwork. Furthermore, because it is a U-shaped formwork with a bottom frame that opens upward, the entire formwork can be made self-supporting.

[0049] Furthermore, in another embodiment of the method for manufacturing a half-precast beam according to the present invention, The first vertical reinforcement further comprises a first upper hook and a first lower hook, The aforementioned second vertical reinforcement further comprises a second upper hook and a second lower hook, At least one of the first lower hooks of the multiple first reinforcing bars of the first reinforced concrete slab, which is positioned first, is an elongated lower hook, longer than the length of all the second upper hooks of the second reinforcing bars of the second reinforced concrete slab, which is positioned second. When lowering the second reinforced precast concrete slab downwards, the long lower hook is passed in advance between the multiple second lower hooks provided on the second reinforced precast concrete slab, or At least one of the second upper hooks of the multiple second reinforcing bars of the second reinforced concrete slab, which is positioned later, is an elongated upper hook, longer than the length of all the first lower hooks of the first reinforcing bars of the first reinforced concrete slab, which is positioned earlier. When lowering the second reinforced precast concrete slab, the long upper hook is passed through the multiple first upper hooks provided on the first reinforced precast concrete slab in advance.

[0050] According to this embodiment, by making at least one of the first lower hooks of the multiple first reinforcing bars of the first reinforced concrete slab that is positioned first a long lower hook that is longer than the length of all the second upper hooks of the second reinforcing bars of the second reinforced concrete slab that is positioned later, when lowering the second reinforced concrete slab, the long lower hook can be passed first between the multiple second lower horizontal bars of the second reinforced concrete slab that is positioned first, thereby allowing the other second lower hooks of the second reinforced concrete slab that is positioned later to be smoothly passed between the multiple first lower horizontal bars of the first reinforced concrete slab that is positioned first.

[0051] Similarly, by making at least one of the second upper hooks of the multiple second reinforcing bars on the second reinforced concrete slab that is positioned later a long upper hook that is longer than the length of all the first lower hooks of the first reinforcing bars on the first reinforced concrete slab that is positioned earlier, when lowering the second reinforced concrete slab, the long upper hook can be passed first between the multiple first upper horizontal bars on the first reinforced concrete slab, allowing the other second upper hooks of the second reinforced concrete slab that is positioned later to be smoothly passed between the multiple first upper horizontal bars on the first reinforced concrete slab that is positioned earlier.

[0052] Here, "at least one of the first lower hooks" includes forms in which only one first lower hook is positioned behind all of the second upper hooks of the second reinforced concrete slab, or forms in which multiple first lower hooks are positioned behind all of the second upper hooks of the second reinforced concrete slab, but with varying lengths among them, or forms in which all of the first lower hooks are positioned behind all of the second upper hooks of the second reinforced concrete slab. Similarly, variations are also included for "at least one of the second upper hooks".

[0053] Furthermore, for example, if at least one of the first lower hooks of the multiple first reinforcing bars on a first reinforced precast concrete slab that is positioned first is a long lower hook, then the other first lower hooks that are not long lower hooks, and the second upper hooks and second lower hooks of the multiple second reinforcing bars on a second reinforced precast concrete slab that is positioned later, and other hooks other than the long lower hook, will have the minimum necessary length.

[0054] Furthermore, in another embodiment of the method for manufacturing a half-precast beam according to the present invention, In the configuration having the long lower hook, of the two first reinforcing bars located at both ends in the longitudinal direction of the first precast concrete slab, the first lower hook of one of the first reinforcing bars is the longest first long lower hook, and the first lower hook of the other first reinforcing bar is the next longest second long lower hook. After passing the first long lower hook through the multiple second lower hooks provided on the second reinforced precast concrete slab, then pass the second long lower hook through the multiple second lower hooks provided on the second reinforced precast concrete slab, or In the configuration having the long upper hook, of the two second reinforcing bars located at both ends in the longitudinal direction of the second precast concrete slab, the second upper hook of one of the second reinforcing bars is the longest first long upper hook, and the second upper hook of the other second reinforcing bar is the next longest second long upper hook. The first long upper hook is passed through the plurality of first upper hooks provided on the first reinforced precast concrete slab, and then the second long upper hook is passed through the plurality of first upper hooks provided on the first reinforced precast concrete slab.

[0055] According to this embodiment, in the configuration having long lower hooks, of the two first reinforcing bars located at both ends in the longitudinal direction of the first precast concrete slab, the first lower hook of one first reinforcing bar is the longest first long lower hook, and the first lower hook of the other first reinforcing bar is the next longest second long lower hook. The first long lower hook is passed first between the multiple second lower cross bars of the second reinforced precast concrete slab which is positioned later, and then the second long lower hook is passed between the multiple second lower cross bars of the second reinforced precast concrete slab. As a result, the first lower hooks located at both ends of the first lower hooks of the multiple first reinforcing bars (the first long lower hook and the second long lower hook) are passed first between the multiple second lower cross bars of the second reinforced precast concrete slab. Therefore, the other first lower hooks located between the first and second long lower hooks can be automatically and smoothly passed between the multiple second lower cross bars of the second reinforced precast concrete slab.

[0056] Similarly, in a configuration having long upper hooks, of the two second reinforcing bars located at both ends in the longitudinal direction of the second precast concrete slab, the second upper hook of one second reinforcing bar is the longest first long upper hook, and the second upper hook of the other second reinforcing bar is the next longest second long upper hook. The first long upper hook is passed first between the multiple first upper horizontal bars of the first reinforced precast concrete slab which has been positioned in advance, and then the second long upper hook is passed between the multiple first upper horizontal bars of the first reinforced precast concrete slab. As a result, the second upper hooks located at both ends of the second upper hooks of the multiple second reinforcing bars (the first long upper hook and the second long upper hook) are passed first between the multiple first upper horizontal bars of the first reinforced precast concrete slab. Therefore, the other second upper hooks located between the first and second long upper hooks can be passed automatically and smoothly between the multiple first upper horizontal bars of the first reinforced precast concrete slab. [Effects of the Invention]

[0057] As can be understood from the above explanation, the half-precast beam and its manufacturing method of the present invention make it possible to reduce the labor required for setting up and removing formwork by using precast concrete slabs that constitute the half-precast beam, while eliminating or reducing the labor required for reinforcing the beam, thereby improving quality. [Brief explanation of the drawing]

[0058] [Figure 1] This is a perspective view of an example of a half-precast beam according to the first embodiment, showing the state before the post-cast concrete body is formed. [Figure 2] This is a perspective view of another example of a half-precast beam according to the first embodiment, showing the state before the post-cast concrete body is formed. [Figure 3] Figures (a) to (f) are process diagrams of the manufacturing method for an example of a half-precast beam according to the first embodiment, and both show a longitudinal cross-sectional view perpendicular to the longitudinal direction of the example of a half-precast beam according to the first embodiment. [Figure 4] Figures (a) to (f) are process diagrams for the manufacturing method of another example of a half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the other example of a half-precast beam according to the first embodiment. [Figure 5] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the yet another example of the half-precast beam according to the first embodiment. [Figure 6] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the yet another example of the half-precast beam according to the first embodiment. [Figure 7] Figures (a) to (c) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the first embodiment. [Figure 8]Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the yet another example of the half-precast beam according to the first embodiment. [Figure 9] (a) and (b) are perspective views of a first reinforced precast concrete slab, which constitutes yet another example of a half-precast beam according to the first embodiment. [Figure 10] (a) to (c) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment. [Figure 11] (a) to (d) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment. [Figure 12] This is a perspective view of a pre-positioned first reinforced precast concrete slab, which constitutes yet another example of a half-precast beam according to the first embodiment. [Figure 13] (a) to (d) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment. [Figure 14] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the yet another example of the half-precast beam according to the first embodiment. [Figure 15] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram also shows a longitudinal section view perpendicular to the longitudinal direction of the yet another example of the half-precast beam according to the first embodiment. [Figure 16] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the embodiment. [Figure 17](a) and (b) are both longitudinal cross-sectional views perpendicular to the longitudinal direction, showing a state in which a first reinforced precast concrete slab and a second reinforced precast concrete slab are assembled, constituting yet another example of a half-precast beam according to the first embodiment. [Figure 18] This is a perspective view of an example of a half-precast beam according to the second embodiment, showing the state before the post-cast concrete body is formed. [Figure 19] This is a perspective view of another example of a half-precast beam according to the second embodiment, before the post-cast concrete body is formed. [Figure 20] Figures (a) to (f) are process diagrams of the manufacturing method for an example of a half-precast beam according to the second embodiment, and both show a longitudinal cross-sectional view perpendicular to the longitudinal direction of the example of a half-precast beam according to the second embodiment. [Figure 21] Figures (a) to (f) are process diagrams for the manufacturing method of another example of a half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of the other example of a half-precast beam according to the second embodiment. [Figure 22] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 23] Figures (a) to (c) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 24] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 25] (a) and (b) are perspective views of a first reinforced precast concrete slab, which constitutes yet another example of a half-precast beam according to the second embodiment. [Figure 26] This is a perspective view of a pre-positioned first reinforced precast concrete slab, which constitutes yet another example of a half-precast beam according to the second embodiment. [Figure 27] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 28] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 29] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 30] Figures (a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, and each diagram shows a longitudinal section perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment. [Figure 31] (a) and (b) are both longitudinal cross-sectional views perpendicular to the longitudinal direction, showing a state in which a first reinforced precast concrete slab and a second reinforced precast concrete slab are assembled, constituting yet another example of a half-precast beam according to the second embodiment. [Figure 32] This is a perspective view of yet another example of a half-precast beam according to the first embodiment, before the post-cast concrete body is formed. [Modes for carrying out the invention]

[0059] Hereinafter, examples of half-precast beams and their manufacturing methods according to each embodiment will be described with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0060] [Half-precast beam according to the first embodiment and its manufacturing method] First, with reference to Figures 1 to 17, several examples of a half-precast beam according to the first embodiment and its manufacturing method will be described. Here, Figures 1 and 2 are perspective views of an example of a half-precast beam according to the first embodiment, before the post-cast concrete body is formed. Figure 3 is a process diagram of the manufacturing method of an example of a half-precast beam according to the first embodiment, in the order of (a) to (f), and shows a longitudinal cross-sectional view perpendicular to the longitudinal direction of the example of a half-precast beam according to the first embodiment.

[0061] The half-precast beam 100 shown in Figure 3(f) comprises a first reinforced precast concrete slab 50A and a second reinforced precast concrete slab 50B arranged with a gap G (see Figure 3(e)), a steel beam 60 placed in the gap G, and a post-cast concrete body 70 provided in the gap G so as to embed the steel beam 60. Here, the steel beam 60 in the illustrated example is an H-shaped steel (including I-shaped steel), but in addition to the H-shaped steel in the illustrated example, it may also be an assembled beam such as a lattice beam having upper and lower chord members and zigzag-shaped lattice members connecting the upper and lower chord members.

[0062] The half-precast beam 100 may be a half-precast beam made of SRC, as shown in Figure 1, in which a first reinforced precast concrete slab 50A, a second reinforced precast concrete slab 50B, and a steel beam 60 are provided along the entire length, and a post-cast concrete body 70 is formed in the gap G. Alternatively, as shown in Figure 2, it may be a half-precast beam of a hybrid structure in which the steel beam 60 is exposed in the central region of the beam and the end regions of the beam are made of SRC (the steel beams at the ends are covered with reinforced concrete).

[0063] As shown in Figure 1, the first reinforced precast concrete slab 50A is formed by attaching a plurality of first reinforcing bars 10A to the first precast concrete slab 20A at intervals along its longitudinal direction, and the second reinforced precast concrete slab 50B is formed by attaching a plurality of second reinforcing bars 10B to the second precast concrete slab 20B at intervals along its longitudinal direction.

[0064] The first reinforcing bar 10A consists of a first longitudinal bar 11A, a first upper transverse bar 12A that bends at the upper end of the first longitudinal bar 11A and extends laterally, a first upper hook 13A that bends at the end of the first upper transverse bar 12A and extends downward, a first lower transverse bar 14A that bends at the lower end of the first longitudinal bar 11A and extends laterally, and a first lower hook 15A that bends at the end of the first lower transverse bar 14A and extends upward, forming a continuous C-shape.

[0065] On the other hand, the second reinforcing bar 10B consists of a second longitudinal bar 11B, a second upper transverse bar 12B that bends at the upper end of the second longitudinal bar 11B and extends laterally, a second upper hook 13B that bends at the end of the second upper transverse bar 12B and extends downward, a second lower transverse bar 14B that bends at the lower end of the second longitudinal bar 11B and extends laterally, and a second lower hook 15B that bends at the end of the second lower transverse bar 14B and extends upward, forming a continuous C-shape.

[0066] Here, the first upper hook 13A and the first lower hook 15A, and the second upper hook 13B and the second lower hook 15B in the illustrated example are all 90-degree hooks.

[0067] The first precast concrete slab 20A has a first vertical slab 22A that extends in the vertical direction, and the first vertical reinforcement bars 11A that extend in the vertical direction are embedded in the first vertical slab 22A, thereby attaching the first reinforcing bars 10A to the first precast concrete slab 20A.

[0068] Similarly, the second precast concrete slab 20B has a second longitudinal slab 22B that extends in the longitudinal direction, and the second longitudinal reinforcement bars 11B that extend in the longitudinal direction are embedded in the second longitudinal slab 22B, thereby attaching the second reinforcing bars 10B to the second precast concrete slab 20B.

[0069] Here, although not shown in the diagram, the thickness of both the first and second precast concrete slabs may be increased, and a portion of the upper and lower main reinforcement bars (for example, one bar each) may be embedded inside the first and second precast concrete slabs. In the configuration where the thickness of the first and second precast concrete slabs is increased, it is preferable that a portion of the upper main reinforcement bars 30 and lower main reinforcement bars 40 are further embedded in addition to the first and second vertical reinforcement bars 11A and 11B, thereby suppressing cracking of the first and second precast concrete slabs that make up the first and second reinforced precast concrete slabs before the half-precast beam is manufactured.

[0070] Multiple upper main reinforcement bars 30 extending in the longitudinal direction are attached below multiple first upper transverse reinforcement bars 12A, and multiple lower main reinforcement bars 40 extending in the longitudinal direction are attached above multiple first lower transverse reinforcement bars 14A. By attaching multiple upper main reinforcement bars 30 and lower main reinforcement bars 40 to the first precast concrete slab 20A to which multiple first reinforcing bars 10A are attached, the first reinforced precast concrete slab 50A is formed.

[0071] Similarly, multiple upper main reinforcement bars 30 extending in the longitudinal direction are attached below multiple second upper transverse reinforcement bars 12B, and multiple lower main reinforcement bars 40 extending in the longitudinal direction are attached above multiple second lower transverse reinforcement bars 14B. By attaching multiple upper main reinforcement bars 30 and lower main reinforcement bars 40 to the second precast concrete slab 20B to which multiple second reinforcing bars 10B are attached, a second reinforced precast concrete slab 50B is formed.

[0072] Here, the entirety of the first reinforced precast concrete slab 50A and the second reinforced precast concrete slab 50B shown in the diagram may be manufactured in a factory or the like, transported to the site and installed in the designated location. Alternatively, the first precast concrete slab 20A, the second precast concrete slab 20B, the upper main reinforcement 30 and the lower main reinforcement 40 may be transported to the site without the upper main reinforcement 30 and the lower main reinforcement 40 being attached (all parts except the upper main reinforcement 30 and the lower main reinforcement 40 may be manufactured in a factory or the like), the first precast concrete slab 20A may be installed in the designated location at the site, the upper main reinforcement 30 and the lower main reinforcement 40 may be attached to form the first reinforced precast concrete slab 50A, and the upper main reinforcement 30 and the lower main reinforcement 40 may be attached to the second precast concrete slab 20B to form the second reinforced precast concrete slab 50B.

[0073] The following explanation will focus on a half-precast beam in the form shown in Figure 1, assuming that the half-precast beam being fabricated is a beam on an upper floor.

[0074] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 3(a), a lower frame 91 is installed at the beam installation position, the first reinforced precast concrete slab 50A (in the illustrated example, the reinforced precast concrete slab on the left) is positioned on the lower frame 91, and a steel beam 60, suspended by a crane or the like (not shown), is placed to the side of the first reinforced precast concrete slab 50A.

[0075] Here, the left-side precast concrete slab 50A with the first reinforcement bar, which is installed first, has four upper main reinforcement bars 30 attached to multiple first upper horizontal reinforcement bars 12A at equal or approximately equal intervals in the horizontal direction, and three lower main reinforcement bars 40 attached to multiple first lower horizontal reinforcement bars 14A at equal or approximately equal intervals in the horizontal direction.

[0076] On the other hand, the right-side precast concrete slab 50B with the second reinforcement bar, which is installed later, has three upper main reinforcement bars 30 attached to multiple second upper horizontal reinforcement bars 12B at equal or approximately equal intervals in the horizontal direction, and four lower main reinforcement bars 40 attached to multiple second lower horizontal reinforcement bars 14B at equal or approximately equal intervals in the horizontal direction.

[0077] As explained below, the first reinforced concrete slab 50A and the second reinforced concrete slab 50B are designed to overlap their first and second reinforcing bars 10A and 10B by placing one upper main reinforcement bar 30 between their first upper hooks 13A and 13B, and one lower main reinforcement bar 40 between their first lower hooks 15A and 15B. However, to prevent interference between the upper main reinforcement bars 30 and the lower main reinforcement bars 40 at the overlapping position of the first and second reinforced concrete slabs 50A and 50B, the upper main reinforcement bars 30 and lower main reinforcement bars 40 at the overlapping position of one of the reinforced concrete slabs are omitted (in the illustrated example, one upper main reinforcement bar 30 and one lower main reinforcement bar 40 are omitted).

[0078] In the illustrated example, the installation of the upper main reinforcement 30 at the lap position is omitted from the left-hand first reinforced precast concrete slab 50A, and the installation of the lower main reinforcement 40 at the lap position is omitted from the right-hand second reinforced precast concrete slab 50B. However, it is also possible to omit the installation of the upper and lower main reinforcement 30 and 40 at the lap position of one of the left and right reinforced precast concrete slabs 50A and 50B, while both the upper and lower main reinforcement 30 and 40 are installed at the lap position of the other precast concrete slab.

[0079] However, in a configuration where one of the reinforced precast concrete slabs lacks both the upper main reinforcement 30 and the lower main reinforcement 40 at the lap position, the amount of reinforcement in the left and right reinforced precast concrete slabs 50A and 50B will differ, resulting in one of the two reinforced precast concrete slabs 50A and 50B becoming excessively heavy. Furthermore, since reinforced precast concrete slabs 50A and 50B are among the heavier members lifted by the crane, in order to reduce the weight of the reinforced precast concrete slabs 50A and 50B as much as possible, it is preferable, as shown in the illustrated example, that the amount of reinforcement in the first reinforced precast concrete slab 50A and the second reinforced precast concrete slab 50B is approximately the same, and that one of the upper main reinforcement and the lower main reinforcement at the lap position is omitted from each.

[0080] Next, as shown in Figure 3(b), the steel beam 60 is moved in the X1 direction and housed inside the reinforced precast concrete slab 50A.

[0081] Next, as shown in Figure 3(c), the reinforced precast concrete slab 50B is moved laterally in the X2 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and the first lower hook 15A of the first reinforced precast concrete slab 50A. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50B has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50A.

[0082] Next, as shown in Figure 3(d), the reinforced precast concrete slab 50B is lowered in the X3 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0083] As shown in Figure 3(d), by completely lowering the reinforced precast concrete slab 50B and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is arranged automatically, and a gap G is formed between the reinforced precast concrete slabs 50A and 50B.

[0084] In this way, when a pair of reinforced precast concrete panels 50A and 50B are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor involved in beam reinforcement work.

[0085] Next, as shown in Figure 3(e), the steel beam 60 is moved in the X4 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50A and 50B and the steel beam 60 in the correct relative positions.

[0086] Next, as shown in Figure 3(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100 having a pair of reinforced precast concrete panels 50A, 50B, a steel beam 60, and a post-cast concrete body 70.

[0087] In the manufacturing method shown in the illustration, the precast concrete panels 20A and 20B function as formwork (side frames) when forming the later-cast concrete body 70, while remaining as components of the half-precast beam 100. This eliminates the need for setting up and removing the side frames, thus saving labor in setting up and removing the formwork.

[0088] Thus, this method of manufacturing a half-precast beam using a pair of reinforced precast concrete panels 50A and 50B allows for labor savings in formwork installation and removal, while eliminating or reducing the labor required for beam reinforcement work. This method offers superior beam manufacturability (or constructability) and improves overall quality.

[0089] Furthermore, because it is made of SRC (steel-reinforced concrete) with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0090] Next, with reference to Figure 4, a method for manufacturing another example of the half-precast beam according to the first embodiment will be described. Here, Figures 4(a) to 4(f) are process diagrams for manufacturing another example of the half-precast beam according to the first embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the first embodiment.

[0091] The reinforced precast concrete slabs 50E and 50F applied to the manufacturing method shown in Figure 4 differ from the reinforced precast concrete slabs 50A and 50B which consist of precast concrete slabs 20A and 20B in that the first precast concrete slab 20E comprises a first vertical slab 22A extending in the vertical direction and a first upper horizontal slab 24A and a first lower horizontal slab 26A extending horizontally from the upper and lower ends of the first vertical slab 22A, respectively; the second precast concrete slab 20F comprises a second vertical slab 22B extending in the vertical direction and a second upper horizontal slab 24B and a second lower horizontal slab 26B extending horizontally from the upper and lower ends of the second vertical slab 22B, respectively; and one upper main reinforcement bar 30 and one lower main reinforcement bar 40 are embedded in each of the upper horizontal slabs 24A and 24B and the lower horizontal slabs 26A and 26B.

[0092] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 4(a), a lower frame 91 is installed at the beam installation position, a reinforced precast concrete slab 50E is positioned on the lower frame 91, and a steel beam 60 is placed to its side.

[0093] Next, as shown in Figure 4(b), the steel beam 60 is moved in the X5 direction and housed inside the reinforced precast concrete slab 50E.

[0094] Next, as shown in Figure 4(c), the reinforced precast concrete slab 50F is moved laterally in the X6 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and the first lower hook 15A of the reinforced precast concrete slab 50A. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50B has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50A.

[0095] Next, as shown in Figure 4(d), the reinforced precast concrete slab 50F is lowered downward in the X7 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0096] As shown in Figure 4(d), by completely lowering the reinforced precast concrete slab 50F and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is arranged automatically, and a gap G is formed between the reinforced precast concrete slabs 50E and 50F.

[0097] In this way, when a pair of reinforced precast concrete panels 50E and 50F are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor involved in beam reinforcement work.

[0098] Next, as shown in Figure 4(e), the steel beam 60 is moved in the X8 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50E and 50F and the steel beam 60 in the correct relative positions.

[0099] Next, as shown in Figure 4(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100A having a pair of reinforced precast concrete panels 50E, 50F, a steel beam 60, and a post-cast concrete body 70.

[0100] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0101] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0102] Furthermore, since the precast concrete panels 20E and 20F are each equipped with a first lower horizontal panel 26A and a second lower horizontal panel 26B, a stable upright posture can be formed when they are installed on the lower frame 91.

[0103] Furthermore, since each of the precast concrete panels 20E and 20F is equipped with a first upper horizontal panel 24A, a second upper horizontal panel 24B, and a first lower horizontal panel 26A, a second lower horizontal panel 26B that extends laterally, an engagement structure can be formed between the pair of upper horizontal panels 24A, 24B and the pair of lower horizontal panels 26A, 26B and the post-cast concrete body 70 provided in the gap G inside them, thereby achieving an even higher degree of integration between the pair of reinforced precast concrete panels 50E, 50F and the post-cast concrete body 70.

[0104] Next, with reference to Figure 5, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 5(a) to (f) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the first embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the first embodiment.

[0105] The pair of reinforced precast concrete slabs 50G and 50H applied to the manufacturing method shown in Figure 5 differ from the reinforced precast concrete slabs 50A and 50B, which consist of precast concrete slabs 20A and 20B, in that the first precast concrete slab 20G comprises a first vertical slab 22A and a first lower horizontal slab 27A extending laterally from the lower end of the first vertical slab 22A, and the second precast concrete slab 20H comprises a second vertical slab 22B and a second lower horizontal slab 27B extending laterally from the lower end of the second vertical slab 22B, and all of the lower main reinforcement bars 40 are embedded in the first lower horizontal slab 27A, and three of the four lower main reinforcement bars 40 are embedded in the second lower horizontal slab 27B.

[0106] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 5(a), a lower frame 91 is installed at the beam installation position, a reinforced precast concrete slab 50G is positioned on the lower frame 91, and a steel beam 60 is placed to its side.

[0107] Next, as shown in Figure 5(b), the steel beam 60 is moved in the X9 direction and housed inside the reinforced precast concrete slab 50G.

[0108] Next, as shown in Figure 5(c), the reinforced precast concrete slab 50H is moved laterally in the X10 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and the first lower hook 15A of the reinforced precast concrete slab 50G. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50H has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50A.

[0109] Next, as shown in Figure 5(d), the reinforced precast concrete slab 50H is lowered downward in the X11 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0110] As shown in Figure 5(d), by completely lowering the reinforced precast concrete slab 50H and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is arranged automatically, and a gap G is formed between the reinforced precast concrete slabs 50G and 50H.

[0111] In this way, when a pair of reinforced precast concrete panels 50G and 50H are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor required for beam reinforcement work.

[0112] Next, as shown in Figure 5(e), the steel beam 60 is moved in the X12 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50G, 50H and the steel beam 60 in the correct relative positions.

[0113] Next, as shown in Figure 5(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100B having a pair of reinforced precast concrete panels 50G, 50H, a steel beam 60, and a post-cast concrete body 70.

[0114] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0115] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0116] Next, with reference to Figure 6, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 6(a) to (f) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the first embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the first embodiment.

[0117] The pair of reinforced precast concrete slabs 50I and 50J applied to the manufacturing method shown in Figure 6 differ from reinforced precast concrete slabs 50A and 50B, which have first reinforcement bars 10A and second reinforcement bars 10B, in that two lower main reinforcement bars 40 are not installed at the lap position of the first lower cross reinforcement bar 14A, and two upper main reinforcement bars 30 are not installed at the lap position of the second upper cross reinforcement bar 12B, that is, they have first reinforcement bars 10C and second reinforcement bars 10D, where the number of upper main reinforcement bars 30 and lower main reinforcement bars 40 at the lap position is two (an example of multiple bars) instead of one.

[0118] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 6(a), a reinforced precast concrete slab 50I is positioned on the lower frame 91, and a steel beam 60 is placed to its side.

[0119] Next, as shown in Figure 6(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50G in the X13 direction.

[0120] Next, as shown in Figure 6(c), the reinforced precast concrete slab 50J is moved laterally in the X14 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and two lower main reinforcement bars 40 are passed between the first upper hook 13A and first lower hook 15A of the reinforced precast concrete slab 50I. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50J has passed the two upper main reinforcement bars 30 on the right side of the reinforced precast concrete slab 50I.

[0121] Next, as shown in Figure 6(d), the reinforced precast concrete slab 50J is lowered in the X15 direction, thereby moving the second upper hook 13B downward so as to straddle the two upper main reinforcements 30 at the lap position.

[0122] As shown in Figure 6(d), by completely lowering the reinforced precast concrete slab 50J and installing it on the lower frame 91, multiple (eight in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the two central upper main reinforcement bars 30 being surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (eight in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the two central lower main reinforcement bars 40 being surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is arranged automatically, and a gap G is formed between the pair of reinforced precast concrete slabs 50I and 50J.

[0123] Next, as shown in Figure 6(e), the steel beam 60 is moved in the X16 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50I and 50J and the steel beam 60 in the correct relative positions.

[0124] Next, as shown in Figure 6(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100C having a pair of reinforced precast concrete panels 50I, 50J, a steel beam 60, and a post-cast concrete body 70.

[0125] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0126] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0127] Next, with reference to Figure 7, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 7(a) to 7(c) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the first embodiment, and both show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the first embodiment.

[0128] The pair of reinforced precast concrete slabs 50K and 50L applied to the manufacturing method shown in Figure 7 differ from reinforced precast concrete slabs 50A and 50B in that the upper parts of the first vertical reinforcement bar 11A of the first reinforcing bar 10A and the second vertical reinforcement bar 11B of the second reinforcing bar 10B protrude from the upper end of the precast concrete slabs 20A and 20B, respectively, and the first reinforcing bar 10A and the second reinforcing bar 10B are installed at a relatively higher position relative to the precast concrete slabs 20A and 20B.

[0129] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 7(a), a pair of reinforced precast concrete slabs 50K and 50L are installed, and a steel beam 60 is placed in the center of the gap G between them. In this state, the first reinforcing bars 10A and 2 reinforcing bars 10B of both slabs, and multiple (seven in the illustrated example) upper main reinforcing bars 30 protrude above the pair of precast concrete slabs 20A and 20B.

[0130] Next, as shown in Figure 7(b), floor lower frames 92 are installed on the left and right sides of the pair of precast concrete slabs 20A and 20B, and upper and lower floor reinforcements 93 are placed so as to penetrate laterally above the first reinforcement bars 10A and the second reinforcement bars 10B and above and below the multiple upper main reinforcement bars 30, and further floor reinforcements 93 are placed in a direction perpendicular to this.

[0131] Next, as shown in Figure 7(c), concrete is poured in a manner that is continuous with the gap G between the pair of reinforced precast concrete slabs 50K and 50L and the space above the lower frame 92 for the floor, thereby forming a post-cast concrete body 70 and a concrete floor slab 70A. In this way, a half-precast beam 100D with a floor is manufactured, which has a pair of reinforced precast concrete slabs 50K and 50L, a steel beam 60, a post-cast concrete body 70, and a concrete floor slab 70A.

[0132] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0133] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0134] Next, with reference to Figure 8, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figure 8 is a process diagram of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, in the order of (a) to (f), and shows a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the first embodiment.

[0135] In the reinforced precast concrete slab 50M shown in Figure 8, there is a first vertical reinforcement 11A and a single row of setting reinforcement 17 that is engaged with the first upper hook 13A, and multiple upper main reinforcement bars 30 are attached to each of the first upper horizontal reinforcement bars 12A and the single row of setting reinforcement bars 17, and there is a first vertical reinforcement 11A and a single row of setting reinforcement bars 17 that is engaged with the first lower horizontal reinforcement bars 14A, and multiple lower main reinforcement bars 40 are attached to each of the first lower horizontal reinforcement bars 14A and the single row of setting reinforcement bars 17, and in the reinforced precast concrete slab 50N, the reinforced precast concrete Unlike the 50M slab, it differs from the pair of reinforced precast concrete slabs 50A and 50B equipped with the first reinforcing bar 10A and the second reinforcing bar 10B in that it has a single row of setting bars 17 that are secured to the second vertical bar 11B and the second lower hook 15B, with multiple lower main bars 40 attached to each of the second lower horizontal bar 14B and the single row of setting bars 17, and it has a single row of setting bars 17 that are secured to the second vertical bar 11B and the second upper horizontal bar 12B, with multiple upper main bars 30 attached to each of the second upper horizontal bar 12B and the single row of setting bars 17.

[0136] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 8(a), one of the reinforced precast concrete panels 50M is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0137] Next, as shown in Figure 8(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50M in the X17 direction.

[0138] Next, as shown in Figure 8(c), the reinforced precast concrete slab 50N is moved laterally in the X18 direction, passing its second lower horizontal reinforcement 14B, second lower hook 15B, and two upper and lower main reinforcement bars 40 between the first upper hook 13A and first lower hook 15A of the reinforced precast concrete slab 50M. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50N has passed the two upper and lower main reinforcement bars 30 on the right side of the reinforced precast concrete slab 50M.

[0139] Next, as shown in Figure 8(d), the reinforced precast concrete slab 50N is lowered downward in the X19 direction, thereby moving the second upper hook 13B downward so as to straddle the two upper and lower main reinforcement bars 30 at the lap position.

[0140] As shown in Figure 8(d), by completely lowering the reinforced precast concrete slab 50N and installing it on the lower frame 91, multiple (7 bars x 2 rows in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the horizontal direction for each of the two overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B and the single row of setting reinforcement bars 17 that are aligned horizontally, and the two upper main reinforcement bars 30 aligned vertically in the center are surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (7 bars x 2 rows in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the horizontal direction for each of the two overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B and a single row of setting reinforcement bars 17 aligned horizontally. The two lower main reinforcement bars 40 aligned vertically in the center are surrounded by the left and right first lower hooks 15A and second lower hooks 15B, and the reinforcement is automatically arranged, forming a gap G between the pair of reinforced precast concrete slabs 50M and 50N.

[0141] Next, as shown in Figure 8(e), the steel beam 60 is moved in the X20 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50M, 50N and the steel beam 60 in the correct relative positions.

[0142] Next, as shown in Figure 8(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100E having a pair of reinforced precast concrete panels 50M, 50N, a steel beam 60, and a post-cast concrete body 70.

[0143] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0144] Furthermore, since multiple upper main reinforcement bars 30 are provided in multiple rows in each section, and multiple lower main reinforcement bars 40 are provided in multiple rows in each section, and the steel beam 60 is embedded inside the post-cast concrete body 70, a high-strength and high-rigidity half-precast beam can be formed.

[0145] Next, with reference to Figure 9, a first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the first embodiment, will be described. Here, Figures 9(a) and 9(b) are both perspective views of a first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the first embodiment.

[0146] The first reinforced precast concrete slab 50P shown in Figure 9(a) has a configuration in which a reinforcing bar 10G with a relatively large cross-sectional diameter is interposed between multiple first reinforcing bars 10A that are attached to the precast concrete slab 20A and arranged in the longitudinal direction.

[0147] The relatively large-diameter reinforcing bars 10G prevent sagging of the first upper horizontal bars 12A and the first lower horizontal bars 14A caused by the weight of the upper main bars 30 and lower main bars 40, as well as swaying when lifted by a crane or the like.

[0148] On the other hand, the first reinforced precast concrete slab 50Q shown in Figure 9(b) has a configuration in which the first auxiliary reinforcement 18A is arranged so as to span from the first upper transverse reinforcement 12A and the first upper hook 13A to the first longitudinal reinforcement 11A, and a separate second auxiliary reinforcement 18B is arranged so as to span from the first lower transverse reinforcement 14A and the first lower hook 15A to the first longitudinal reinforcement 11A, and has a first reinforcing bar 10H.

[0149] The upper and lower auxiliary reinforcements 18A and 18B prevent the sagging of the first upper horizontal reinforcement 12A to which the upper main reinforcement 30 is attached, and the sagging of the first lower horizontal reinforcement 14A to which the lower main reinforcement 40 is attached.

[0150] Although not shown in the diagram, the second reinforced precast concrete slab, which is paired with the first reinforced precast concrete slab 50P and 50Q, has the same reinforcement configuration as the first reinforced precast concrete slab 50P and 50Q.

[0151] Next, with reference to Figure 10, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 10(a) to (c) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, in that order.

[0152] The pair of reinforced precast concrete slabs 50R and 50S applied to the manufacturing method shown in Figure 10 differ from reinforced precast concrete slabs 50A and 50B in that the first upper hook 13C of the first reinforcing bar 10I of one reinforced precast concrete slab 50R is a 135-degree hook and the first lower hook 15A is a 90-degree hook, while the second upper hook 13B of the second reinforcing bar 10J of the other reinforced precast concrete slab 50S is a 90-degree hook and the second lower hook 15C is a 135-degree hook.

[0153] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 10(a), one reinforced precast concrete slab 50R is positioned on the lower frame 91, the steel beam 60 is housed inside the reinforced precast concrete slab 50R, and the other reinforced precast concrete slab 50S is placed to its side.

[0154] Next, as shown in Figure 10(b), the reinforced precast concrete slab 50S is moved laterally in the X21 direction, and its second lower horizontal reinforcement 14B, second lower hook 15C, and one lower main reinforcement 40 are passed between the first upper hook 13C and first lower hook 15A of the reinforced precast concrete slab 50R. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50S has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50R.

[0155] Next, as shown in Figure 10(c), the reinforced precast concrete slab 50S is lowered downward in the X22 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0156] As shown in Figure 10(c), by completely lowering the reinforced precast concrete slab 50S and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13C and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15C. The reinforcement is automatically arranged, and a gap G is formed between the pair of reinforced precast concrete slabs 50R and 50S. By moving the steel beam 60 to the center of the gap G and pouring concrete into the gap G, a half-precast beam (not shown) will be manufactured.

[0157] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0158] Furthermore, the upper main reinforcement 30 at the lap position is surrounded by a second upper hook 13B which is a 90-degree hook and a first upper hook 13C which is a 135-degree hook, and similarly, the lower main reinforcement 40 at the lap position is surrounded by a first lower hook 15A which is a 90-degree hook and a second lower hook 15C which is a 135-degree hook, thereby improving the stress transfer between the first reinforcing bars 10I and the second reinforcing bars 10J of a pair of reinforced precast concrete panels 50R and 50S.

[0159] Next, with reference to Figure 11, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 11(a) to (d) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, in that order.

[0160] The pair of reinforced precast concrete slabs 50T and 50U applied to the manufacturing method shown in Figure 11 differ from reinforced precast concrete slabs 50R and 50S, which are equipped with first reinforcement bars 10I and second reinforcement bars 10J, in that the first upper hook 13C of the first reinforcing bar 10K of one reinforced precast concrete slab 50T is a 135-degree hook, and the first lower hook 15D is a 135-degree hook with its tip bent and extending in the 90-degree direction, while the second upper hook 13D of the second reinforcing bar 10L of the other reinforced precast concrete slab 50U is a 135-degree hook with its tip bent and extending in the 90-degree direction, and the second lower hook 15C is a 135-degree hook.

[0161] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 11(a), one reinforced precast concrete slab 50T is positioned on the lower frame 91, the steel beam 60 is housed inside the reinforced precast concrete slab 50T, and the other reinforced precast concrete slab 50U is placed to its side.

[0162] Next, as shown in Figure 11(b), the reinforced precast concrete slab 50U is moved laterally in the X23 direction, and its second lower horizontal reinforcement 14B, second lower hook 15C, and one lower main reinforcement 40 are passed between the first upper hook 13C and first lower hook 15D of the reinforced precast concrete slab 50T. The lateral movement is stopped when the second upper hook 13D of the reinforced precast concrete slab 50U passes the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50T.

[0163] Next, as shown in Figure 11(c), the reinforced precast concrete slab 50U is lowered downward in the X24 direction, causing the second upper hook 13D to move downward so as to straddle the upper main reinforcement 30 at the lap position. As is clear from Figure 11(c), the second upper hook 13D and the first lower hook 15D have portions 13a and 15a that bend at a 90-degree angle to the tip of the 135-degree hook. By sliding the second upper hook 13D and the first lower hook 15D vertically along the 135-degree hooks, the first upper hook 13C and the second lower hook 15C, ultimately forming a lap position where one upper main reinforcement 30 or lower main reinforcement 40 is sandwiched between the two 135-degree hooks, as shown in Figure 11(d).

[0164] As shown in Figure 11(d), by completely lowering the reinforced precast concrete slab 50U in the X25 direction and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper transverse bars 12A and second upper transverse bars 12B, with the central upper main reinforcement bar 30 being surrounded by the left and right first upper hooks 13C and second upper hooks 13D. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower transverse bars 14A and second lower transverse bars 14B, with the central lower main reinforcement bar 40 being surrounded by the left and right first lower hooks 15D and second lower hooks 15C. The reinforcement is automatically arranged, and a gap G is formed between the pair of reinforced precast concrete slabs 50T and 50U. By moving the steel beam 60 to the center of the gap G and pouring concrete into the gap G, a half-precast beam (not shown) will be manufactured.

[0165] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0166] Furthermore, since the upper main reinforcement bars 30 at the lap position are surrounded by the first upper hook 13C and the second upper hook 13D, both of which are 135-degree hooks, and similarly the lower main reinforcement bars 40 at the lap position are surrounded by the first lower hook 15D and the second lower hook 15C, both of which are 135-degree hooks, the stress transfer between the first reinforcing bars 10K and the second reinforcing bars 10L of a pair of reinforced precast concrete panels 50T and 50U can be improved.

[0167] Next, with reference to Figures 12 and 13, a method for manufacturing yet another example of the half-precast beam according to the first embodiment will be described. Here, Figure 12 is a perspective view of a pre-positioned first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the first embodiment. Figures 13(a) to (d) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the first embodiment, in that order.

[0168] The first reinforced precast concrete slab 50V shown in Figure 12 differs from the reinforced precast concrete slab 50A in that, among the multiple (nine in the illustrated example) reinforcing bars attached to the precast concrete slab 20A, the lengths t3 and t2 of the first lower hooks 15E and 15F of the reinforcing bars 10M and 10N at both ends in the longitudinal direction are longer than the length t1 of the lower hooks 15A of the other seven first reinforcing bars 10A.

[0169] More specifically, of the first reinforcing bars 10M and 10N, the length t3 of the long lower hook 15E of one of the first reinforcing bars 10M is set to be longer than the length t2 of the long lower hook 15F of the other first reinforcing bar 10N, and the relationship between the lengths t3, t2, and t1 of the long lower hooks 15E (first long lower hook), 15F (second long lower hook), and 1st lower hook 15A is set to t3 > t2 > t1.

[0170] Here, the length t1 of the first lower hook 15A of the first reinforcing bar 10A, and the length of the first upper hook 13A, should be the minimum necessary length.

[0171] As shown in Figure 13, in the fabrication of the half-precast beam, the precast concrete slab 50V shown in Figure 12 is positioned first, and the precast concrete slab 50B, which is positioned later, has all the same length second upper hooks 13B and all the same length second lower hooks 15B, as explained above.

[0172] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 13(a), one reinforced precast concrete slab 50V is positioned on the lower frame 91, the steel beam 60 is housed inside the reinforced precast concrete slab 50V, and the other reinforced precast concrete slab 50B is placed to its side.

[0173] Next, as shown in Figure 13(b), the reinforced precast concrete slab 50B is moved laterally in the X26 direction, and its second lower horizontal reinforcement 15B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and the long lower hook 15E of the reinforced precast concrete slab 50V. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50B has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50V.

[0174] Next, as shown in Figure 13(c), by lowering the reinforced precast concrete slab 50B downward in the X27 direction, the first long lower hook 15E of the first reinforcing bar 10M, which is the longest of the nine first reinforcing bars 10A, 10M, and 10N provided in the reinforced precast concrete slab 50V, is passed between the multiple second lower horizontal bars 14B of the reinforced precast concrete slab 50B.

[0175] Furthermore, by lowering the reinforced precast concrete slab 50B downwards in the X27 direction, the second long lower hook 15F of the next long first reinforcing bar 10M will be passed between the multiple second lower horizontal bars 14B of the reinforced precast concrete slab 50B.

[0176] In this way, by first focusing on passing the first long lower hook 15E between multiple second lower horizontal bars 14B, and then focusing on passing the second long lower hook 15F between multiple second lower horizontal bars 14B, once the long lower hooks 15E and 15F of the first reinforcing bars 10M and 10N at both ends of the nine first reinforcing bars 10A, 10M, and 10N have passed between the corresponding multiple second lower horizontal bars 14B, the reinforcing precast concrete slabs 50V and 50B on the left and right can be made parallel to each other.

[0177] Therefore, as shown in Figure 13(c), the reinforced precast concrete slab 50B can be smoothly lowered in the X27 direction, and as shown in Figure 13(c), by completely lowering the reinforced precast concrete slab 50B and installing it in the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 being on the left. The first upper hook 13A and the second upper hook 13B on the right surround the main lower reinforcement bars 40. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are placed at equal or approximately equal intervals in the lateral direction for both the first lower horizontal reinforcement bars 14A and the second lower horizontal reinforcement bars 14B, which overlap each other. The central lower main reinforcement bar 40 is surrounded by the left and right first lower hooks 15A (15E, 15F) and the second lower hook 15B, and the reinforcement is automatically arranged, creating a gap G between the pair of reinforced precast concrete slabs 50V and 50B. Next, as shown in Figure 13(d), the steel beam 60 is moved in the X28 direction to the center of the gap G, and concrete is poured into the gap G to produce the half-precast beam 100F.

[0178] Here, as shown in the illustrated example, in addition to the configuration in which the first lower hooks of the first reinforcing bars at both ends of the multiple first reinforcing bars provided in the left-side first reinforcing bar precast concrete slab that is positioned in advance are long lower hooks, there may also be a configuration in which the first lower hook of any one of the first reinforcing bars is a long lower hook, or for example, there may be a configuration in which the first lower hooks of three or more first reinforcing bars are long lower hooks and all of the long lower hooks are of different lengths (none of which are shown).

[0179] Furthermore, although not shown in the illustration, the manufacturing method may involve positioning the left and right precast concrete slabs with first and second reinforcement by first and second reinforcement by first positioning by first positioning the right precast concrete slab with second reinforcement by first positioning the right precast concrete slab with second reinforcement by first positioning the right precast concrete slab with second reinforcement by first positioning the right precast concrete slab with second reinforcement by first positioning the long upper hooks of the multiple first upper horizontal reinforcements of the left precast concrete slab with first reinforcement by first positioning the long upper hooks of the multiple first upper horizontal reinforcements of the left precast concrete slab with first reinforcement by first positioning the right precast concrete slab with second

[0180] In this configuration as well, of the two second reinforcing bars located at both ends in the longitudinal direction of the second precast concrete slab, the second upper hook of one second reinforcing bar is made the longest first long upper hook, and the second upper hook of the other second reinforcing bar is made the next longest second long upper hook. The first long upper hook is passed first between the multiple first upper horizontal bars of the left first reinforced precast concrete slab, and then the second long upper hook is passed between the multiple first upper horizontal bars of the left first reinforced precast concrete slab. This allows the left and right reinforced precast concrete slabs to be positioned parallel to each other, and the right reinforced precast concrete slab to be lowered smoothly to position both.

[0181] Next, with reference to Figure 14, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 14(a) to (f) are process diagrams for the manufacturing method of another example of the half-precast beam according to the first embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the first embodiment.

[0182] The pair of reinforced precast concrete slabs 50W and 50X applied to the manufacturing method shown in Figure 14 differ from the reinforced precast concrete slabs 50A and 50B equipped with precast concrete slabs 20A and 20B in that the first vertical slab 22A and the second vertical slab 22B that extend vertically in the direction of the precast concrete slabs 20I and 20J each have a first upper recess 28A and a first lower recess 29A, and a second upper recess 28B and a second lower recess 29B on the inside of their upper and lower ends, respectively, and the upper main reinforcement bars 30 adjacent to the first upper recess 28A and the second upper recess 28B are separated laterally, and the lower main reinforcement bars 40 adjacent to the first lower recess 29A and the second lower recess 29B are separated laterally.

[0183] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 14(a), a reinforced precast concrete slab 50W is positioned on the lower frame 91, and a steel beam 60 is placed to its side.

[0184] Next, as shown in Figure 14(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50W in the X29 direction.

[0185] Next, as shown in Figure 14(c), the reinforced precast concrete slab 50X is moved laterally in the X30 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and the first lower hook 15A of the reinforced precast concrete slab 50W. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50X has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50W.

[0186] Next, as shown in Figure 14(d), the reinforced precast concrete slab 50X is lowered downward in the X31 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0187] As shown in Figure 14(d), by completely lowering the reinforced precast concrete slab 50X and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is arranged automatically, and a gap G is formed between the pair of reinforced precast concrete slabs 50W and 50X.

[0188] Next, as shown in Figure 14(e), the steel beam 60 is moved in the X32 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50W, 50X and the steel beam 60 in the correct relative positions.

[0189] Next, as shown in Figure 14(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100G having a pair of reinforced precast concrete panels 50W, 50X, a steel beam 60, and a post-cast concrete body 70.

[0190] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0191] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0192] Furthermore, the first vertical slab 22A of the precast concrete slab 20I has a first upper recess 28A and a first lower recess 29A on the inside of its upper and lower ends, respectively, and the upper main reinforcement 30 and lower main reinforcement 40 adjacent to the first upper recess 28A and the first lower recess 29A are separated laterally, and the second vertical slab 22B of the precast concrete slab 20J has a second upper recess 28B and a second lower recess 29B on the inside of its upper and lower ends, respectively. Because the upper main reinforcement bars 30 and lower main reinforcement bars 40 adjacent to the second upper recess 28B and the second lower recess 29B are spaced apart laterally, the concrete used to form the post-cast concrete body 70 can sufficiently wrap around the upper main reinforcement bars 30 and lower main reinforcement bars 40 adjacent to the first vertical slab 22A and the second vertical slab 22B, allowing the upper main reinforcement bars 30 and lower main reinforcement bars 40 placed at the ends to be embedded without gaps inside the post-cast concrete body 70.

[0193] Next, with reference to Figure 15, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 15(a) to (f) are process diagrams for the manufacturing method of another example of the half-precast beam according to the first embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the first embodiment.

[0194] In the manufacturing method shown in Figure 15, a pair of precast concrete slabs 50Y and 50Z with third and fourth reinforcement bars are used, and each of the separate first longitudinal bars 11P and separate second longitudinal bars 11Q that form a U-shape are embedded at intervals along the longitudinal direction of the precast concrete slabs 20A and 20B, and each of the separate first upper transverse bars 12P and separate first lower transverse bars 14P that form each of the separate first reinforcing bars 10P It differs from the reinforced precast concrete panels 50A and 50B in that the first upper transverse bars 12A and first lower transverse bars 14A of each of the multiple C-shaped first reinforcing bars 10A are arranged overlapping and tied together, and the second upper transverse bars 12B and second lower transverse bars 14B of each of the multiple C-shaped second reinforcing bars 10B are arranged overlapping and tied together with each of the separate second upper transverse bars 12Q and separate second lower transverse bars 14Q that form each separate second reinforcing bar 10Q.

[0195] The separate first reinforcing bar 10P is formed by the continuous arrangement of the separate first longitudinal bar 11P, the separate first upper transverse bar 12P which bends at the upper end of the separate first longitudinal bar 11P and extends laterally, and the separate first lower transverse bar 14P which bends at the lower end of the separate first longitudinal bar 11P and extends laterally, forming a U-shape.

[0196] On the other hand, the separate second reinforcing bar 10Q is formed by a series of separate second longitudinal bars 11Q, a separate second upper transverse bar 12Q which bends at the upper end of the separate second longitudinal bar 11Q and extends laterally, and a separate second lower transverse bar 14Q which bends at the lower end of the separate second longitudinal bar 11Q and extends laterally, forming a U-shape.

[0197] For the first longitudinal slab 22A of the precast concrete panel 20A, multiple separate first reinforcing bars 10P are embedded at intervals along its longitudinal direction, and the corresponding first upper transverse bars 12A and first lower transverse bars 14A of the first reinforcing bar 10A are arranged to overlap with the separate first upper transverse bars 12P and separate first lower transverse bars 14P of each separate first reinforcing bar 10P, and are then tied or welded together.

[0198] Similarly, for the second longitudinal slab 22B of the precast concrete slab 20B, multiple separate second reinforcing bars 10Q each have their own separate second longitudinal bars 11Q embedded at intervals along the longitudinal direction, and the corresponding second upper transverse bars 12B and second lower transverse bars 14B of the second reinforcing bar 10B are arranged to overlap with the separate second upper transverse bars 12Q and separate second lower transverse bars 14Q of each separate second reinforcing bar 10Q, and are then tied or welded together.

[0199] Multiple upper main reinforcement bars 30 extending in the longitudinal direction are attached below multiple first upper transverse reinforcement bars 12A and second upper transverse reinforcement bars 12B, and multiple lower main reinforcement bars 40 extending in the longitudinal direction are attached above multiple first lower transverse reinforcement bars 14A and second lower transverse reinforcement bars 14B, thereby forming a third reinforced precast concrete slab 50Y and a fourth reinforced precast concrete slab 50Z.

[0200] Here, the entire reinforced precast concrete slab 50Y, 50Z shown in the diagram may be manufactured in a factory, etc., transported to the site and installed in the designated location. Alternatively, the precast concrete slabs 20A, 20B, the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 may be transported to the site with the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 not attached (all parts except the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 being manufactured in a factory, etc.), and the precast concrete slabs 20A, 20B, the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 not attached (all parts except the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 not attached), and the precast concrete slabs 20A, 20B, the first reinforcement bar 10A, the second reinforcement bar 10B, the upper main reinforcement bar 30, and the lower main reinforcement bar 40 not attached, After the concrete slab 20A is installed, the first reinforcing bar 10A may be attached to a separate first reinforcing bar 10P, and the upper main reinforcing bar 30 and lower main reinforcing bar 40 may be attached to the first reinforcing bar 10A to form the third reinforced precast concrete slab 50Y. Alternatively, the second reinforcing bar 10B may be attached to a separate second reinforcing bar 10Q attached to the precast concrete slab 20B, and the upper main reinforcing bar 30 and lower main reinforcing bar 40 may be attached to the second reinforcing bar 10B to form the fourth reinforced precast concrete slab 50Y.

[0201] Furthermore, the precast concrete slabs 20A and 20B, along with the upper and lower main reinforcements 30 and 40, may be transported to the site without the upper and lower main reinforcements 30 and 40 being attached (all parts except the upper and lower main reinforcements 30 and 40 are manufactured in a factory, etc.). After the precast concrete slab 20A is installed in its designated position at the site, the upper and lower main reinforcements 30 and 40 are attached to the first reinforcing bar 10A to form the third reinforced precast concrete slab 50Y. In addition, the upper and lower main reinforcements 30 and 40 are attached to the second reinforcing bar 10B attached to the precast concrete slab 20B to form the fourth reinforced precast concrete slab 50Z.

[0202] Here, although not shown in the diagram, there may be a configuration in which a first reinforcing bar 10A is provided between a first reinforcing bar 10A connected to a separate first reinforcing bar 10P, without the other separate first reinforcing bar 10P present. For example, in addition to the first reinforcing bars 10A connected to a separate first reinforcing bar 10P, a first reinforcing bar 10A that is not connected to a separate first reinforcing bar 10P may be provided. In other words, any number of first reinforcing bars 10A from the multiple first reinforcing bars 10A constituting the first reinforced concrete slab 50A shown in Figure 1 may be provided in place of the first reinforcing bars 10A connected to the separate first reinforcing bar 10P in this embodiment. In this way, by combining the first reinforcing bars 10A of different embodiments, it is possible to provide a number of first reinforcing bars 10A that can obtain the desired shear reinforcement effect. The same applies to the second reinforcing bar 10B connected to a separate second reinforcing bar 10Q.

[0203] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 15(a), one of the reinforced precast concrete panels 50Y is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0204] Next, as shown in Figure 15(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50Y in the X33 direction.

[0205] Next, as shown in Figure 15(c), the reinforced precast concrete slab 50Z is moved laterally in the X34 direction, and its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 are passed between the first upper hook 13A and first lower hook 15A of the reinforced precast concrete slab 50Y. The lateral movement is stopped when the second upper hook 13B of the reinforced precast concrete slab 50Z passes the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50Y.

[0206] Next, as shown in Figure 15(d), the reinforced precast concrete slab 50Z is lowered downward in the X35 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0207] As shown in Figure 15(d), by completely lowering the reinforced precast concrete slab 50Z and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is automatically arranged, and a gap G is formed between the pair of reinforced precast concrete slabs 50Y and 50Z.

[0208] Next, as shown in Figure 15(e), the steel beam 60 is moved in the X36 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50Y, 50Z and the steel beam 60 in the correct relative positions.

[0209] Next, as shown in Figure 15(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100H having a pair of reinforced precast concrete panels 50Y, 50Z, a steel beam 60, and a post-cast concrete body 70.

[0210] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0211] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0212] Furthermore, in addition to the U-shaped separate first reinforcing bars 10P and 2 reinforcing bars 10Q embedded in the precast concrete slabs 20A and 20B, the entire C-shaped first reinforcing bar 10A and 2 reinforcing bar 10B, which are tied together, are embedded in the post-cast concrete body 70, thereby further enhancing the shear reinforcement effect of the first reinforcing bar 10A and 2 reinforcing bar 10B. As a result, even if the degree of integration between the precast concrete slabs 20A and 20B and the post-cast concrete body 70 is not good, a high shear reinforcement effect will be achieved by the C-shaped first reinforcing bar 10A and 2 reinforcing bar 10B.

[0213] Next, with reference to Figure 16, a manufacturing method for yet another example of the half-precast beam according to the first embodiment will be described. Here, Figures 16(a) to (f) are process diagrams for the manufacturing method of another example of the half-precast beam according to the first embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the first embodiment.

[0214] The pair of precast concrete slabs 50Y' and 50Z' with reinforced third bars, applied to the manufacturing method shown in Figure 16, differ from precast concrete slabs 50Y and 50Z in that a first corrugated reinforcement bar 19A (truss reinforcement) that extends longitudinally and exhibits a corrugated shape is connected to the first longitudinal reinforcement bar 11P of the separate first reinforcement bar 10P and the first longitudinal reinforcement bar 11A of the first reinforcement bar 10A, and a second corrugated reinforcement bar 19B (truss reinforcement) that extends longitudinally and exhibits a corrugated shape is connected to the second longitudinal reinforcement bar 11Q of the separate second reinforcement bar 10Q and the second longitudinal reinforcement bar 11B of the second reinforcement bar 10B.

[0215] Each member is joined to the others by welding or other means to the peaks and valleys of the first corrugated reinforcing bars 19A and 19B, respectively, to the separate first longitudinal bars 11P and 11A, and to the separate second longitudinal bars 11Q and 21B.

[0216] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 16(a), one of the reinforced precast concrete panels 50Y' is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0217] Next, as shown in Figure 16(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50Y' in the X37 direction.

[0218] Next, as shown in Figure 16(c), the reinforced precast concrete slab 50Z' is moved laterally in the X38 direction, passing its second lower horizontal reinforcement 14B, second lower hook 15B, and one lower main reinforcement 40 between the first upper hook 13A and first lower hook 15A of the reinforced precast concrete slab 50Y', and stopping the lateral movement when the second upper hook 13B of the reinforced precast concrete slab 50Z' has passed the one upper main reinforcement 30 on the right side of the reinforced precast concrete slab 50Y'.

[0219] Next, as shown in Figure 16(d), the reinforced precast concrete slab 50Z' is lowered in the X39 direction, thereby moving the second upper hook 13B downward so as to straddle one of the upper main reinforcement bars 30 at the lap position.

[0220] As shown in Figure 16(d), by completely lowering the reinforced precast concrete slab 50Z' and installing it on the lower frame 91, multiple (seven in the illustrated example) upper main reinforcement bars 30 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first upper horizontal reinforcement bars 12A and second upper horizontal reinforcement bars 12B, with the central upper main reinforcement bar 30 being surrounded by the left and right first upper hooks 13A and second upper hooks 13B. Similarly, multiple (seven in the illustrated example) lower main reinforcement bars 40 are arranged at equal or approximately equal intervals in the lateral direction for both the overlapping first lower horizontal reinforcement bars 14A and second lower horizontal reinforcement bars 14B, with the central lower main reinforcement bar 40 being surrounded by the left and right first lower hooks 15A and second lower hooks 15B. The reinforcement is automatically arranged, and a gap G is formed between the pair of reinforced precast concrete slabs 50Y' and 50Z'.

[0221] Next, as shown in Figure 16(e), the steel beam 60 is moved in the X40 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete slabs 50Y', 50Z' and the steel beam 60 in the correct relative positions.

[0222] Next, as shown in Figure 16(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100I having a pair of reinforced precast concrete panels 50Y', 50Z', a steel beam 60, and a post-cast concrete body 70.

[0223] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0224] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0225] Furthermore, by connecting the first longitudinal bar 11A of the C-shaped first reinforcing bar 10A and the separate first longitudinal bar 11P of the U-shaped separate first reinforcing bar 10P with the first wavy reinforcing bar 19A that extends in the longitudinal direction and exhibits a wavy shape, a stronger integration of the two can be achieved. Similarly, by connecting the second longitudinal bar 11B of the C-shaped second reinforcing bar 10B and the separate second longitudinal bar 11Q of the U-shaped separate second reinforcing bar 10Q with the second wavy reinforcing bar 19B that extends in the longitudinal direction and exhibits a wavy shape, a stronger integration of the two can be achieved. Furthermore, this configuration allows the first vertical reinforcement 11A, the separate first vertical reinforcement 11P, and the first corrugated reinforcement 19A between them, as well as the second vertical reinforcement 11B, the separate second vertical reinforcement 11Q, and the second corrugated reinforcement 19B between them, to resist, in the same manner as a truss beam, the pressure acting on the inside of the precast concrete slabs 20A and 20B when concrete is poured during the construction of the post-cast concrete body 70, and the earth pressure acting on the outside of the precast concrete slabs 20A and 20B when soil is backfilled before concrete is poured.

[0226] The half-precast beams and their manufacturing methods, which are applied to the beams of the upper floors of buildings, have been described above with reference to Figures 1 to 16. However, as shown in Figure 17, half-precast beams may also be applied to the foundation beams of buildings. Here, Figures 17(a) and (b) are both longitudinal cross-sectional views perpendicular to the longitudinal direction, showing a pair of reinforced precast concrete slabs assembled, which constitute yet another example of the half-precast beam according to the first embodiment. Both show examples of the pair of reinforced precast concrete slabs 50M and 50N, which were described with reference to Figure 8, being applied to a foundation beam.

[0227] In the example shown in Figure 17(a), a leveling material (for example, crushed stone 95 or lean concrete 96) is laid on the excavated and prepared ground surface to ensure levelness. A pair of reinforced precast concrete slabs 50M and 50N are placed on top of the lean concrete 96, forming a gap G between them, and a steel beam 60 is placed in the center of the gap G. By pouring concrete into the gap G, a foundation beam, which is a half-precast beam (not shown), is fabricated.

[0228] On the other hand, the example shown in Figure 17(b) involves installing a precast concrete slab 20K that also serves as a lower frame on top of crushed stone 95, and then fitting the lower ends of a pair of reinforced precast concrete slabs 50M and 50N into a pair of recesses 25 provided on the upper surface of the precast concrete slab 20K.

[0229] Since the lower end of the reinforced precast concrete slab 50M, 50N is fitted into the recess 25 of the lower frame-type precast concrete slab 20K, it is possible to maintain a stable upright position of the reinforced precast concrete slab 50M, 50N while eliminating the need for the installation of leveling materials.

[0230] [Half-precast beam according to the second embodiment and its manufacturing method] Next, with reference to Figures 18 to 31, several examples of half-precast beams and their manufacturing methods according to the second embodiment will be described. Here, Figures 18 and 19 are perspective views of an example of a half-precast beam according to the second embodiment, before the post-cast concrete body is formed. Figures 20(a) to 20(f) are process diagrams of the manufacturing method of an example of a half-precast beam according to the second embodiment, and both show a longitudinal cross-sectional view perpendicular to the longitudinal direction of the example of a half-precast beam according to the second embodiment.

[0231] The half-precast beam 100' shown in Figure 20(f) comprises a first reinforced precast concrete slab 50A' and a second reinforced precast concrete slab 50B' arranged with a gap G (see Figure 20(e)), a steel beam 60 placed in the gap G, and a post-cast concrete body 70 provided in the gap G so as to embed the steel beam 60.

[0232] The half-precast beam 100' may be a half-precast beam made of SRC, as shown in Figure 18, in which a first reinforced precast concrete slab 50A' and a second reinforced precast concrete slab 50B' and a steel beam 60 are provided along the entire length, and a post-cast concrete body 70 is formed in the gap G. Alternatively, as shown in Figure 19, it may be a half-precast beam of hybrid structure in which the steel beam 60 is exposed in the central region of the beam and the end regions of the beam are made of SRC (the steel beams at the ends are covered with reinforced concrete).

[0233] As shown in Figure 18, the first reinforced precast concrete slab 50A' is formed by attaching a plurality of first reinforcing bars 10A' to the first precast concrete slab 20A at intervals along its longitudinal direction, and the second reinforced precast concrete slab 50B' is formed by attaching a plurality of second reinforcing bars 10B' to the second precast concrete slab 20B at intervals along its longitudinal direction.

[0234] The first reinforcing bar 10A' consists of a first longitudinal bar 11A', a first upper transverse bar 12A' that bends at the upper end of the first longitudinal bar 11A' and extends laterally, a first upper hook 13A' that bends at the end of the first upper transverse bar 12A' and extends diagonally downward, and a first lower hook 15A' (180-degree hook) that bends at the lower end of the first longitudinal bar 11A' and extends upward, forming a roughly L-shape. Here, the first upper hook 13A' in the illustrated example is a 135-degree hook, but it may also be a 90-degree hook or a 180-degree hook.

[0235] On the other hand, the second reinforcing bar 10B' consists of a second longitudinal bar 11B', a second lower transverse bar 14B' that bends at the lower end of the second longitudinal bar 11B' and extends laterally, a second lower hook 15B' that bends at the end of the second lower transverse bar 14B' and extends diagonally upward, and a second upper hook 13B' (180-degree hook) that bends above the second longitudinal bar 11B' and extends downward, forming a roughly L-shape. Here, the second lower hook 15B' in the illustrated example is a 135-degree hook, but it may also be a 90-degree hook or a 180-degree hook.

[0236] The first precast concrete slab 20A' has a first vertical slab 22A' that extends in the vertical direction, and the first vertical reinforcement bars 11A' that extend in the vertical direction are embedded in the first vertical slab 22A, thereby attaching the first reinforcing bars 10A' to the first precast concrete slab 20A'.

[0237] Similarly, the second precast concrete slab 20B' has a second longitudinal slab 22B' that extends in the longitudinal direction, and the second longitudinal reinforcement bars 11B' that extend in the longitudinal direction are embedded in the second longitudinal slab 22B, thereby attaching the second reinforcing bars 10B' to the second precast concrete slab 20B'.

[0238] Here, although not shown in the diagram, the thickness of both the first and second precast concrete slabs may be increased, and a portion of the upper and lower main reinforcement bars (for example, one bar each) may be embedded inside the first and second precast concrete slabs. In the configuration where the thickness of the first and second precast concrete slabs is increased, it is preferable that a portion of the upper main reinforcement bars 30 and lower main reinforcement bars 40 are further embedded in addition to the first and second vertical reinforcement bars 11A' and 11B', thereby suppressing cracking of the first and second precast concrete slabs that make up the first and second reinforced precast concrete slabs before the half-precast beam is manufactured.

[0239] Multiple upper main reinforcement bars 30 extending in the longitudinal direction are attached below multiple first upper transverse reinforcement bars 12A', and multiple lower main reinforcement bars 40 extending in the longitudinal direction are attached above multiple second lower transverse reinforcement bars 14B'. By attaching multiple upper main reinforcement bars 30 to the first precast concrete slab 20A' to which multiple first reinforcing bars 10A' are attached, the first reinforced precast concrete slab 50A' is formed, and by attaching multiple lower main reinforcement bars 40 to the second precast concrete slab 20B' to which multiple second reinforcing bars 10B' are attached, the second reinforced precast concrete slab 50B' is formed.

[0240] Here, the entirety of the first reinforced precast concrete slab 50A' and the second reinforced precast concrete slab 50B' shown in the diagram may be manufactured in a factory or the like, transported to the site and installed in the designated location. Alternatively, the first precast concrete slab 20A', the second precast concrete slab 20B', the upper main reinforcement 30, and the lower main reinforcement 40 may be transported to the site without the upper main reinforcement 30 and lower main reinforcement 40 attached (all parts except the upper main reinforcement 30 and lower main reinforcement 40 may be manufactured in a factory or the like), the first precast concrete slab 20A' may be installed in the designated location at the site, the upper main reinforcement 30 may be attached to form the first reinforced precast concrete slab 50A', and the lower main reinforcement 40 may be attached to the second precast concrete slab 20B' to form the second reinforced precast concrete slab 50B'.

[0241] The following explanation will focus on a half-precast beam in the form shown in Figure 18, assuming that the half-precast beam being fabricated is a beam on an upper floor.

[0242] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 20(a), a lower frame 91 is installed at the beam installation position, a reinforced precast concrete slab 50A' (in the illustrated example, the reinforced precast concrete slab on the left) is positioned on the lower frame 91, and a steel beam 60, suspended by a crane or the like (not shown), is placed to the side of the reinforced precast concrete slab 50A'.

[0243] Here, the precast concrete slab 50A' with the first reinforcing bars installed in advance on the left side has seven upper main reinforcing bars 30 attached at equal or substantially equal intervals in the horizontal direction with respect to a plurality of first upper horizontal reinforcing bars 12A'.

[0244] On the other hand, the precast concrete slab 50B' with reinforcing bars installed later has seven lower main reinforcing bars 40 attached at equal or substantially equal intervals in the horizontal direction with respect to a plurality of second lower horizontal reinforcing bars 14B'.

[0245] As will be described below, the precast concrete slabs 50A' and 50B' with reinforcing bars are configured such that one upper main reinforcing bar 30 is included inside where the first upper hooks 13A' and the second upper hooks 13B' of both cross each other, and one lower main reinforcing bar 40 is included inside where the first lower hooks 15A' and the second lower hooks 15B' of both cross each other, thereby integrating the first reinforcing bars 10A' and the second reinforcing bars 10B'.

[0246] Next, as shown in Fig. 20(b), the steel beam 60 is moved and accommodated in the X41 direction inside the precast concrete slab 50A' with reinforcing bars.

[0247] Next, as shown in Fig. 20(c), the precast concrete slab 50B' with reinforcing bars is laterally moved in the X42 direction, and the lateral movement is stopped at a position where the lower main reinforcing bar 40 at the left end passes through the first lower hook 15A' and the second upper hook 13B' passes through the upper main reinforcing bar 30 at the right end.

[0248] Next, as shown in Fig. 20(d), the precast concrete slab 50B' with reinforcing bars is lowered in the X43 direction downward, so that the lower main reinforcing bar 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcing bar 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0249] As shown in Figure 20(d), by completely lowering the reinforced precast concrete slab 50B' and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the reinforced precast concrete slabs 50A' and 50B'.

[0250] In this way, when a pair of reinforced precast concrete panels 50A' and 50B' are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor involved in beam reinforcement work.

[0251] Next, as shown in Figure 20(e), the steel beam 60 is moved in the X44 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50A', 50B' and the steel beam 60 in the correct relative positions.

[0252] Next, as shown in Figure 20(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100' having a pair of reinforced precast concrete panels 50A', 50B', a steel beam 60, and a post-cast concrete body 70.

[0253] In the manufacturing method shown in the illustration, the precast concrete panels 20A and 20B function as formwork (side frames) when forming the later-cast concrete body 70, while remaining as components of the half-precast beam 100'. This eliminates the need for setting up and removing the side frames, thus saving labor in setting up and removing the formwork.

[0254] Thus, this method of manufacturing a half-precast beam using a pair of reinforced precast concrete panels 50A', 50B' allows for labor savings in formwork installation and removal, while eliminating or reducing the labor required for beam reinforcement work. This method offers superior beam manufacturability (or constructability) and improves overall quality.

[0255] Furthermore, because it is made of SRC (steel-reinforced concrete) with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0256] Next, with reference to Figure 21, a method for manufacturing another example of the half-precast beam according to the second embodiment will be described. Here, Figures 21(a) to (f) are process diagrams for manufacturing another example of the half-precast beam according to the second embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the second embodiment.

[0257] The first precast concrete slab 20E' constituting the reinforced precast concrete slab 50E' applied to the manufacturing method shown in Figure 21 differs from the reinforced precast concrete slabs 50A' and 50B' that consist of precast concrete slabs 20A' and 20B' in that the first precast concrete slab 20E' constituting the reinforced precast concrete slab 50E' comprises a first vertical slab 22A' extending in the vertical direction and a first upper horizontal slab 24A' extending horizontally from the upper end of the first vertical slab 22A', and the second precast concrete slab 20F' constituting the reinforced precast concrete slab 50F' comprises a second vertical slab 22B' extending in the vertical direction and a second lower horizontal slab 26B' ​​extending horizontally from the lower end of the second vertical slab 22B'.

[0258] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 21(a), a lower frame 91 is installed at the beam installation position, a reinforced precast concrete slab 50E' is positioned on the lower frame 91, and a steel beam 60 is placed to the side of the reinforced precast concrete slab 50E'.

[0259] Next, as shown in Figure 21(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50E' in the X45 direction.

[0260] Next, as shown in Figure 21(c), the precast concrete slab 50F' is moved laterally in the X46 direction, and the lateral movement is stopped when the lower main reinforcement 40 at the left end passes the first lower hook 15A' and the second upper hook 13B' passes the upper main reinforcement 30 at the right end.

[0261] Next, as shown in Figure 21(d), the reinforced precast concrete slab 50F' is lowered downward in the X47 direction, so that the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0262] As shown in Figure 21(d), by completely lowering the reinforced precast concrete slab 50F' and installing it on the lower frame 91, the lower main reinforcement bars 40 at the left end are sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement bars 30 at the right end are sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the first reinforced precast concrete slab 50E' and the second reinforced precast concrete slab 50F'.

[0263] Next, as shown in Figure 21(e), the steel beam 60 is moved in the X48 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50E', 50F' and the steel beam 60 in the correct relative positions.

[0264] Next, as shown in Figure 21(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100A' having a pair of reinforced precast concrete panels 50E', 50F', a steel beam 60, and a post-cast concrete body 70.

[0265] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0266] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0267] Next, with reference to Figure 22, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 22(a) to (f) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the second embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment.

[0268] The first precast concrete slab 20G' that makes up the precast concrete slab with reinforcing bars 50G' applicable to the manufacturing method shown in Fig. 22 includes a first vertical slab 22A and a first lower horizontal slab 27A' that extends horizontally from the lower end of the first vertical slab 22A'. The second precast concrete slab 20H' that makes up the precast concrete slab with reinforcing bars 50H' includes a second vertical slab 22B' and a second lower horizontal slab 27B' that extends horizontally from the lower end of the second vertical slab 22B'. The first lower hook 15A' is located above the first lower horizontal slab 27A'. Six out of all (seven in the illustrated example) of the lower main reinforcing bars 40 are embedded in the second lower horizontal slab 27B'. The second lower hook 15B' and the remaining one lower main reinforcing bar 40 project laterally from the end of the second lower horizontal slab 27B'. This is different from the precast concrete slabs with reinforcing bars 50A' and 50B' that include the precast concrete slabs 20A' and 20B'.

[0269] Regarding the manufacturing method of the illustrated example, first, as shown in Fig. 22(a), install the lower frame 91 at the installation position of the beam, position the precast concrete slab with reinforcing bars 50G' on the lower frame 91, and arrange the steel beam 60 on the side of the precast concrete slab with reinforcing bars 50G'.

[0270] Next, as shown in Fig. 22(b), move the steel beam 60 in the X49 direction into the interior of the precast concrete slab with reinforcing bars 50G' and accommodate it.

[0271] Next, as shown in Fig. 22(c), horizontally move the precast concrete slab 50H' in the X50 direction and stop the horizontal movement at a position where the lower main reinforcing bar 40 at the left end passes through the first lower hook 15A' and the second upper hook 13B' passes through the upper main reinforcing bar 30 at the right end.

[0272] Next, as shown in Fig. 22(c), lower the precast concrete slab with reinforcing bars 50H' downward in the X51 direction so that the lower main reinforcing bar 40 at the left end is sandwiched by the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcing bar 30 at the right end is sandwiched by the first upper hook 13A' and the second upper hook 13B'.

[0273] As shown in Figure 22(d), by completely lowering the reinforced precast concrete slab 50H' and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the reinforced precast concrete slabs 50G' and 50H'.

[0274] Next, as shown in Figure 22(e), the steel beam 60 is moved in the X52 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50G', 50H' and the steel beam 60 in the correct relative positions.

[0275] Next, as shown in Figure 22(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100B' having a pair of reinforced precast concrete panels 50G', 50H', a steel beam 60, and a post-cast concrete body 70.

[0276] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0277] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0278] Next, with reference to Figure 23, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 23(a) to (c) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the second embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment.

[0279] The pair of reinforced precast concrete slabs 50K' and 50L' applied to the manufacturing method shown in Figure 23 differ from the reinforced precast concrete slabs 50A' and 50B' in that the upper parts of the first vertical reinforcement 11A' of the first reinforcing bar 10A' and the second vertical reinforcement 11B' of the second reinforcing bar 10B' protrude from the upper end of the precast concrete slabs 20A' and 20B', respectively, and the first reinforcing bar 10A' and the second reinforcing bar 10B' are installed at a relatively higher position relative to the precast concrete slabs 20A' and 20B'.

[0280] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 23(a), a pair of reinforced precast concrete slabs 50K' and 50L' are installed, and a steel beam 60 is placed in the center of the gap G between them. In this state, the first reinforcing bars 10A' and the second reinforcing bars 10B' of both slabs, and multiple (seven in the illustrated example) upper main reinforcing bars 30 protrude above the pair of precast concrete slabs 20A' and 20B'.

[0281] Next, as shown in Figure 23(b), floor lower frames 92 are installed on the left and right sides of a pair of precast concrete slabs 20A' and 20B', and upper and lower floor reinforcements 93 are placed so as to penetrate laterally above the first reinforcement bars 10A' and the second reinforcement bars 10B' and above and below the multiple upper main reinforcement bars 30, and further floor reinforcements 93 are placed in a direction perpendicular to this.

[0282] Next, as shown in Figure 23(c), concrete is poured in a manner that is continuous with the gap G between the pair of reinforced precast concrete slabs 50K' and 50L' and the space above the lower frame 92 for the floor, thereby forming a post-cast concrete body 70 and a concrete floor slab 70A. In this way, a half-precast beam 100D' with a floor is manufactured, which has a pair of reinforced precast concrete slabs 50K' and 50L', a steel beam 60, a post-cast concrete body 70, and a concrete floor slab 70A.

[0283] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0284] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0285] Next, with reference to Figure 24, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 24(a) to (f) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the second embodiment, and together they show a longitudinal section view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the second embodiment.

[0286] As shown in Figure 24(a), the first reinforcing bar 10E' constituting the reinforced precast concrete slab 50M' has a single-stage setting bar 17 that is locked to the first vertical bar 11A' and the first upper hook 13A', and multiple upper main reinforcements 30 are attached to each of the first upper horizontal bar 12A' and the single-stage setting bar 17. The second reinforcing bar 10F' constituting the reinforced precast concrete slab 50N' has a single-stage setting bar 17 that is locked to the second vertical bar 11B' and the second lower hook 15B', and multiple lower main reinforcements 40 are attached to each of the second lower horizontal bar 14B' and the single-stage setting bar 17. These differences are compared to the reinforced precast concrete slabs 50A' and 50B' which have the first reinforcing bar 10A' and second reinforcing bar 10B'.

[0287] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 24(a), a lower frame 91 is installed at the beam installation position, a reinforced precast concrete slab 50M' is positioned on the lower frame 91, and a steel beam 60 is placed to the side of the reinforced precast concrete slab 50M'.

[0288] Next, as shown in Figure 24(b), the steel beam 60 is moved in the X53 direction and housed inside the reinforced precast concrete slab 50M'.

[0289] Next, as shown in Figure 24(c), the reinforced precast concrete slab 50N' is moved laterally in the X54 direction, and the lateral movement is stopped when the two lower main reinforcements 40 at the left end pass the first lower hook 15A' and the second upper hook 13B' passes the two upper main reinforcements 30 at the right end.

[0290] Next, as shown in Figure 24(c), the reinforced precast concrete slab 50N' is lowered downward in the X55 direction, so that the two lower main reinforcements 40 at the left end are sandwiched between the first lower hook 15A' and the second lower hook 15B', and the two upper main reinforcements 30 at the right end are sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0291] As shown in Figure 24(d), by completely lowering the reinforced precast concrete slab 50N' and installing it on the lower frame 91, the first lower hook 15A' and the second lower hook 15B' hold the two lower main reinforcements 40 at the left end, and the first upper hook 13A' and the second upper hook 13B' hold the two upper main reinforcements 30 at the right end. With the first upper horizontal reinforcement 12A' and one row of preparation reinforcement 17 aligned horizontally, multiple upper main reinforcements 30 (7 in the illustrated example, 2 rows) are arranged at equal or approximately equal intervals horizontally for each row of preparation reinforcement 17, and multiple lower main reinforcements 40 (7 in the illustrated example, 2 rows) are arranged at equal or approximately equal intervals horizontally for each row of preparation reinforcement 17 aligned horizontally for each row of preparation reinforcement 17, 2 lower horizontal reinforcement 14B'. The reinforcement is automatically arranged, and a gap G is formed between the reinforced precast concrete slabs 50M' and 50N'.

[0292] Next, as shown in Figure 24(e), the steel beam 60 is moved in the X56 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete slabs 50M', 50N' and the steel beam 60 in the correct relative positions.

[0293] Next, as shown in Figure 24(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100E' having a pair of reinforced precast concrete panels 50M', 50N', a steel beam 60, and a post-cast concrete body 70.

[0294] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0295] Furthermore, since multiple upper main reinforcement bars 30 are provided in multiple rows in each section, and multiple lower main reinforcement bars 40 are provided in multiple rows in each section, and the steel beam 60 is embedded inside the post-cast concrete body 70, a high-strength and high-rigidity half-precast beam can be formed.

[0296] Next, with reference to Figure 25, a first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the second embodiment, will be described. Here, Figures 25(a) and (b) are both perspective views of the first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the second embodiment.

[0297] The reinforced precast concrete slab 50P' shown in Figure 25(a) has a configuration in which a first reinforcing bar 10G' with a relatively large cross-sectional diameter is interposed between a plurality of first reinforcing bars 10A' attached to the precast concrete slab 20A' and arranged in the longitudinal direction.

[0298] The relatively large diameter first reinforcing bars 10G' prevent sagging of each first upper transverse bar 12A' caused by the weight of the upper main bars 30, as well as swaying when lifted by a crane or the like.

[0299] On the other hand, the reinforced precast concrete slab 50Q' shown in Figure 25(b) has a configuration in which the first auxiliary reinforcement 18A is arranged so as to span the first upper transverse reinforcement 12A' and the first upper hook 13A' and the first longitudinal reinforcement 11A', and has a first reinforcing bar 10H'.

[0300] The first auxiliary reinforcement 18A prevents the first upper transverse reinforcement 12A' to which the upper main reinforcement 30 is attached from sagging. Here, the first reinforcing bars 10H' may be arranged in multiples along the longitudinal direction of the reinforced precast concrete slab 50Q', or they may be arranged in combination with other embodiments. For example, in the reinforced precast concrete slab 50P' shown in Figure 25(a), the first reinforcing bar 10H' may be provided instead of the first reinforcing bar 10A'.

[0301] Although not shown in the diagram, the second reinforced precast concrete slab, which is paired with the first reinforced precast concrete slab 50P', 50Q', has the same reinforcement configuration as the first reinforced precast concrete slab 50P', 50Q'.

[0302] Next, with reference to Figures 26 and 27, a method for manufacturing yet another example of the half-precast beam according to the second embodiment will be described. Here, Figure 26 is a perspective view of a pre-positioned first reinforced precast concrete slab, which constitutes yet another example of the half-precast beam according to the second embodiment. Figures 27(a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, in that order.

[0303] The reinforced precast concrete slab 50V' shown in Figure 26 differs from the reinforced precast concrete slab 50A' in that, among the multiple (nine in the illustrated example) reinforcing bars attached to the precast concrete slab 20A', the lengths t6 and t5 of the first lower hooks 15I' and 15J' of the first reinforcing bars 10M' and 10N' at both ends in the longitudinal direction are longer than the length t4 of the lower hooks 15A' of the other seven first reinforcing bars 10A', making them long lower hooks.

[0304] More specifically, among the first reinforcing bars 10M' and 10N', the length t3 of the long lower hook 15I' of one of the first reinforcing bars 10M' is set to be longer than the length t2 of the long lower hook 15J' of the other first reinforcing bar 10N', and the relationship between the lengths t6, t5, and t4 of the long lower hooks 15I' (first long lower hook), 15J' (second long lower hook), and 1st lower hook 15A' is set to t6 > t5 > t4.

[0305] Here, the length t4 of the first lower hook 15A' of the first reinforcing bar 10A' and the length of the first upper hook 13A' should be the minimum necessary length.

[0306] As shown in Figure 27, in the fabrication of the half-precast beam, the precast concrete slab 50V' shown in Figure 26 is positioned first, and the precast concrete slab 50B' that is positioned later has all the same length second upper hooks 13B' and all the same length second lower hooks 15B', as explained above.

[0307] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 27(a), one of the reinforced precast concrete panels 50V' is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0308] Next, as shown in Figure 27(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50V' in the X57 direction.

[0309] Next, as shown in Figure 27(c), the reinforced precast concrete slab 50B' is moved laterally in the X58 direction, and the lateral movement is stopped when the lower main reinforcement 40 at the left end passes the first lower hook 15A' and the second upper hook 13B' passes the upper main reinforcement 30 at the right end.

[0310] Next, as shown in Figure 27(d), by lowering the reinforced precast concrete slab 50B' downward in the X59 direction, the first long lower hook 15I' of the first reinforcing bar 10M', which is the longest of the nine first reinforcing bars 10A', 10M', and 10N' provided in the first reinforced precast concrete slab 50V', is passed between the multiple second lower horizontal bars 14B' of the reinforced precast concrete slab 50B'.

[0311] Furthermore, by lowering the reinforced precast concrete slab 50B' downwards in the X59 direction, the second long lower hook 15J' of the longer first reinforcing bar 10N' will be passed between the multiple second lower horizontal bars 14B' of the second reinforced precast concrete slab 50B'.

[0312] In this way, by first focusing on passing the first long lower hook 15I' between multiple second lower horizontal bars 14B', and then focusing on passing the second long lower hook 15J' between multiple second lower horizontal bars 14B', once the long lower hooks 15I' and 15J' of the first reinforcing bars 10M' and 10N' at both ends of the nine first reinforcing bars 10A', 10M', and 10N' have passed between the corresponding multiple second lower horizontal bars 14B', the reinforcing precast concrete slabs 50V' and 50B' on the left and right can be made parallel to each other.

[0313] Therefore, as shown in Figure 27(c), the reinforced precast concrete slab 50B' can be smoothly lowered in the X59 direction, and as shown in Figure 27(d), by completely lowering the reinforced precast concrete slab 50B' and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15C' (and other first lower hooks 15A') and the corresponding second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. With this arrangement, multiple upper main reinforcement bars 30 (seven in the illustrated example) are placed at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are placed at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the reinforced precast concrete slabs 50V' and 50B'.

[0314] Next, as shown in Figure 27(e), the steel beam 60 is moved in the X60 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete slabs 50V', 50B' and the steel beam 60 in the correct relative positions.

[0315] Next, as shown in Figure 27(10Hf), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100F' having a pair of reinforced precast concrete panels 50V', 50B', a steel beam 60, and a post-cast concrete body 70.

[0316] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0317] Here, as shown in the illustrated example, in addition to the configuration in which the first lower hooks of the first reinforcing bars at both ends of the multiple first reinforcing bars provided in the precast concrete slab with the first reinforcing bars that are positioned in advance are long lower hooks, there may also be a configuration in which the first lower hook of any one of the first reinforcing bars is a long lower hook, or for example, there may be a configuration in which the first lower hooks of three or more first reinforcing bars are long lower hooks and all of the long lower hooks are of different lengths (none of which are shown).

[0318] Furthermore, although not shown in the illustration, at least one of the second upper hooks of the multiple second reinforcing bars on the second reinforced precast concrete slab, which is positioned later, is a long upper hook, longer than the length of all the first lower hooks of the first reinforcing bars on the first reinforced precast concrete slab, which is positioned earlier. In this manufacturing method, when lowering the second reinforced precast concrete slab, the long upper hook is passed first between the multiple first upper horizontal bars on the first reinforced precast concrete slab, and then the first reinforced precast concrete slab and the second reinforced precast concrete slab are positioned.

[0319] In this configuration, of the two second reinforcing bars located at both ends in the longitudinal direction of the second reinforced concrete slab, the second upper hook of one of the second reinforcing bars is made the longest first long upper hook, and the second upper hook of the other second reinforcing bar is made the next longest second long upper hook. By passing the first long upper hook first between the multiple first upper horizontal bars of the first reinforced concrete slab, and then passing the second long upper hook between the multiple first upper horizontal bars of the first reinforced concrete slab, the first reinforced concrete slab and the second reinforced concrete slab on the left and right can be made to be parallel to each other, and the second reinforced concrete slab can be smoothly lowered and positioned.

[0320] Next, with reference to Figure 28, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 28(a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, in that order.

[0321] The first precast concrete slab 20I' that constitutes the reinforced precast concrete slab 50W', which is applied to the manufacturing method shown in Figure 28, differs from the reinforced precast concrete slabs 50A' and 50B' that consist of precast concrete slabs 20A' and 20B' in that the first vertical slab 22A' of the first precast concrete slab 20I' that extends vertically has a first upper recess 28A' and a first lower recess 29A' on the inside of its upper and lower ends, respectively, and the upper main reinforcement 30 adjacent to the first upper recess 28A' is separated laterally, and the second vertical slab 22B' of the second precast concrete slab 20J' that constitutes the reinforced precast concrete slab 50X', differs from the reinforced precast concrete slabs 50A' and 50B' that consist of precast concrete slabs 20A' and 20B' in that the second vertical slab 22B' of the second precast concrete slab 20J' that extends vertically has a second upper recess 28B' and a second lower recess 29B' on the inside of its upper and lower ends, respectively, and the lower main reinforcement 40 adjacent to the second lower recess 29B' is separated laterally.

[0322] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 28(a), a reinforced precast concrete slab 50W' is positioned on the lower frame 91, and a steel beam 60 is placed to its side.

[0323] Next, as shown in Figure 28(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50W' in the X61 direction.

[0324] Next, as shown in Figure 28(c), the reinforced precast concrete slab 50X' is moved laterally in the X62 direction, and the lateral movement is stopped when the lower main reinforcement 40 at the left end passes the first lower hook 15A' and the second upper hook 13B' passes the upper main reinforcement 30 at the right end.

[0325] Next, as shown in Figure 28(d), the reinforced precast concrete slab 50X' is lowered downward in the X63 direction, so that the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0326] As shown in Figure 28(d), by completely lowering the reinforced precast concrete slab 50X' and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the reinforced precast concrete slabs 50W' and 50X'.

[0327] Next, as shown in Figure 28(e), the steel beam 60 is moved in the X64 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50W', 50X' and the steel beam 60 in the correct relative positions.

[0328] Next, as shown in Figure 28(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100G' having a pair of reinforced precast concrete panels 50W', 50X', a steel beam 60, and a post-cast concrete body 70.

[0329] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0330] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0331] Furthermore, the first vertical slab 22A' of the precast concrete slab 20I' has a first upper recess 28A' and a first lower recess 29A' on the inside of its upper and lower ends, respectively, and the upper main reinforcement 30 adjacent to the first upper recess 28A' is spaced laterally apart. The second vertical slab 22B' of the precast concrete slab 20J' has a second upper recess 28B' and a second lower recess 29B' on the inside of its upper and lower ends, respectively, and the lower main reinforcement 40 adjacent to the second lower recess 29B' is spaced laterally apart. As a result, the concrete used to form the post-cast concrete body 70 can sufficiently wrap around the upper main reinforcement 30 and lower main reinforcement 40 adjacent to the first vertical slab 22A' and the second vertical slab 22B', and the upper main reinforcement 30 and lower main reinforcement 40 placed at the ends can be embedded without gaps inside the post-cast concrete body 70.

[0332] Next, with reference to Figure 29, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 29(a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, in that order.

[0333] The third reinforced precast concrete slab 50Y' applied to the manufacturing method shown in Figure 29 has separate first vertical bars 11P' that form a plurality of separate first reinforcing bars 10P' which are roughly L-shaped, embedded at intervals along the longitudinal direction of the first precast concrete slab 20A', and each of the separate first upper horizontal bars 12P' of the plurality of roughly L-shaped first reinforcing bars 10A' is arranged to overlap with each of the separate first upper horizontal bars 12P' that form each of the separate first reinforcing bars 10P', and is tied together, etc., and the fourth reinforced precast concrete slab Cast concrete slab 50Z' differs from reinforced precast concrete slabs 50A and 50B in that each of the separate second vertical bars 11Q' forming a plurality of separate second reinforcing bars 10Q' which are roughly L-shaped is embedded at intervals along the longitudinal direction of the second precast concrete slab 20B', and each of the separate second horizontal bars 14Q' of the plurality of separate second reinforcing bars 10B' which are roughly L-shaped is arranged to overlap with each of the separate second horizontal bars 14Q' forming each of the separate second reinforcing bars 10Q', and is tied together or otherwise secured.

[0334] The separate first reinforcing bar 10P' is formed by a series of separate first longitudinal bars 11P', separate first upper transverse bars 12' that bend at the upper end of the separate first longitudinal bar 11P' and extend laterally, and separate first lower hooks 15P' that bend at the lower end of the separate first longitudinal bar 11P' and extend upward, forming a roughly L-shape.

[0335] On the other hand, the separate second reinforcing bar 10Q' is formed by a series of separate second longitudinal bars 11Q', a separate second lower transverse bar 14Q' that bends at the lower end of the separate second longitudinal bar 11Q' and extends laterally, and a separate second upper hook 13Q' that bends at the upper end of the separate second longitudinal bar 11Q' and extends downward, forming a roughly L-shape.

[0336] For the first precast concrete slab 20A', a plurality of separate first reinforcing bars 10P' are embedded in the first longitudinal slab 22A' at intervals along its longitudinal direction, and the first upper transverse bar 12A' of the corresponding first reinforcing bar 10A' is placed over the separate first upper transverse bar 12P' of each separate first reinforcing bar 10P' and then tied or welded together. A plurality of upper main reinforcing bars 30 extending in the longitudinal direction are attached below the plurality of first upper transverse bars 12A' to form the third reinforced precast concrete slab 50Y'.

[0337] On the other hand, for the second longitudinal slab 22B' of the second precast concrete slab 20B', multiple separate second reinforcing bars 10Q' are embedded at intervals in the longitudinal direction, and the second lower transverse bars 14B' of the corresponding second reinforcing bars 10B' are arranged to overlap with the separate second lower transverse bars 14Q' of each separate second reinforcing bar 10Q' and then tied or welded together. Multiple lower main reinforcing bars 40 extending in the longitudinal direction are attached above the multiple second lower transverse bars 14B', thereby forming the fourth reinforced precast concrete slab 50Z'.

[0338] Here, the entirety of the third reinforced concrete slab 50Y' and the fourth reinforced concrete slab 50Z' shown in the diagram may be manufactured in a factory, etc., transported to the site and installed in the installation position, or the first reinforcement bar 10A', the second reinforcement bar 10B', the upper main reinforcement bar 30, and the lower main reinforcement bar 40 may be not attached (all parts except the first reinforcement bar 10A', the second reinforcement bar 10B', the upper main reinforcement bar 30, and the lower main reinforcement bar 40 may be manufactured in a factory, etc.) The precast concrete slab 20A', the second precast concrete slab 20B', the first reinforcing bars 10A', the second reinforcing bars 10B', the upper main reinforcement bars 30 and the lower main reinforcement bars 40 may be transported to the site, and after the first precast concrete slab 20A' is installed at the site, the first reinforcing bar 10A' may be attached to a separate first reinforcing bar 10P', and the upper main reinforcement bars 30 may be attached to the first reinforcing bar 10A' to form the third reinforced precast concrete slab 50Y'. In this case, the transported components of the fourth reinforced precast concrete slab 50Z' will also be attached to each other in the same way as the third reinforced precast concrete slab 50Y'.

[0339] Furthermore, although not shown in the diagram, there may be a configuration in which a first reinforcing bar 10A' is arranged between a first reinforcing bar 10A' that is connected to a separate first reinforcing bar 10P', without the corresponding separate first reinforcing bar 10P'. For example, by arranging a first reinforcing bar 10A' that is not connected to a separate first reinforcing bar 10P', in addition to the first reinforcing bar 10A' that is connected to a separate first reinforcing bar 10P', it is possible to arrange a number of first reinforcing bars 10A' that can obtain the desired shear reinforcement effect, without depending on the number of separate first reinforcing bars 10P'. The same applies to a configuration in which a second reinforcing bar 10B' is arranged between a second reinforcing bar 10B' that is tied to a separate second reinforcing bar 10Q', without the corresponding separate second reinforcing bar 10Q'.

[0340] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 29(a), one of the reinforced precast concrete panels 50Y' is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0341] Next, as shown in Figure 29(b), the steel beam 60 is moved and housed inside the reinforced precast concrete slab 50Y' in the X65 direction.

[0342] Next, as shown in Figure 29(c), the reinforced precast concrete slab 50Z' is moved laterally in the X66 direction, and the lateral movement is stopped when the lower main reinforcement 40 at the left end passes the first lower hook 15A' and the second upper hook 13B' passes the upper main reinforcement 30 at the right end.

[0343] Next, as shown in Figure 29(d), the reinforced precast concrete slab 50Z' is lowered downward in the X67 direction, so that the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0344] As shown in Figure 29(d), by completely lowering the reinforced precast concrete slab 50Z' and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the third reinforced precast concrete slab 50Y' and the fourth reinforced precast concrete slab 50Z'.

[0345] Next, as shown in Figure 29(e), the steel beam 60 is moved in the X68 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50Y', 50Z' and the steel beam 60 in the correct relative positions.

[0346] Next, as shown in Figure 29(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100G' having a pair of reinforced precast concrete panels 50Y', 50Z', a steel beam 60, and a post-cast concrete body 70.

[0347] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0348] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0349] Furthermore, since the entirety of the roughly L-shaped first reinforcing bars 10A' and 2B', which are tied together to the roughly L-shaped first reinforcing bars 10P' and 2Q' embedded in the precast concrete slabs 20A' and 20B', can be embedded in the later-cast concrete body 70, the shear reinforcement effect of the first reinforcing bars 10A' and 2B' can be further enhanced. As a result, even if the degree of integration between the precast concrete slabs 20A' and 20B' and the later-cast concrete body 70 is not good, a high shear reinforcement effect can be achieved by the roughly L-shaped first reinforcing bars 10A' and 2B'.

[0350] Next, with reference to Figure 30, a manufacturing method for yet another example of the half-precast beam according to the second embodiment will be described. Here, Figures 30(a) to (f) are process diagrams of the manufacturing method for yet another example of the half-precast beam according to the second embodiment, in that order.

[0351] The pair of precast concrete slabs 50Y" and 50Z" with reinforced third bars, applied to the manufacturing method shown in Figure 30, differ from the precast concrete slabs 50Y' and 50Z' in that a first wave-shaped reinforcement bar 19A (truss reinforcement) that extends vertically and exhibits a wave-like shape is connected to the separate first longitudinal reinforcement bar 11P' of the separate first reinforcement bar 10P' and the first longitudinal reinforcement bar 11A' of the separate first reinforcement bar 10A', and a second wave-shaped reinforcement bar 19B (truss reinforcement) that extends vertically and exhibits a wave-like shape is connected to the separate second longitudinal reinforcement bar 11Q' of the separate second reinforcement bar 10Q' and the second longitudinal reinforcement bar 11B' of the second reinforcement bar 10B'.

[0352] Each member is joined to the others by welding or other means to the peaks and valleys of the first corrugated reinforcing bars 19A and 19B, respectively, to the separate first longitudinal bars 11P' and 11A', and to the separate second longitudinal bars 11Q' and 21B'.

[0353] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 30(a), one of the reinforced precast concrete panels 50Y" is positioned on the lower frame 91, and the steel beam 60 is placed to its side.

[0354] Next, as shown in Figure 30(b), the steel beam 60 is moved in the X37 direction and housed inside the reinforced precast concrete slab 50Y".

[0355] Next, as shown in Figure 30(c), the reinforced precast concrete slab 50Z" is moved laterally in the X70 direction, and the lateral movement is stopped when the lower main reinforcement 40 at the left end passes the first lower hook 15A' and the second upper hook 13B' passes the upper main reinforcement 30 at the right end.

[0356] Next, as shown in Figure 30(d), the reinforced precast concrete slab 50Z" is lowered downward in the X71 direction, so that the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'.

[0357] As shown in Figure 30(d), by completely lowering the reinforced precast concrete slab 50Z" and installing it on the lower frame 91, the lower main reinforcement 40 at the left end is sandwiched between the first lower hook 15A' and the second lower hook 15B', and the upper main reinforcement 30 at the right end is sandwiched between the first upper hook 13A' and the second upper hook 13B'. Multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the first upper horizontal reinforcement bar 12A', and multiple lower main reinforcement bars 40 (seven in the illustrated example) are arranged at equal or approximately equal intervals horizontally with respect to the second lower horizontal reinforcement bar 14B', thereby automatically arranging the reinforcement and creating a gap G between the third reinforced precast concrete slab 50Y" and the fourth reinforced precast concrete slab 50Z".

[0358] Next, as shown in Figure 30(e), the steel beam 60 is moved in the X72 direction to the center of the gap G, thereby arranging the pair of reinforced precast concrete panels 50Y" and 50Z" and the steel beam 60 in the correct relative positions.

[0359] Next, as shown in Figure 30(f), concrete is poured into the gap G and the steel beam 60 is embedded to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100I' having a pair of reinforced precast concrete panels 50Y" and 50Z", a steel beam 60, and a post-cast concrete body 70.

[0360] The manufacturing method shown in the illustration reduces the labor involved in setting up and removing formwork, eliminates or reduces the labor required for reinforcing beams, and results in a manufacturing method that offers excellent manufacturability for beams and improves quality.

[0361] Furthermore, because it is made of SRC with a steel beam 60 embedded inside the post-cast concrete body 70, it is possible to form a half-precast beam that is both high-strength and highly rigid.

[0362] Furthermore, by connecting the first longitudinal bar 11A' of the roughly L-shaped first reinforcing bar 10A' and the separate first longitudinal bar 11P' of the separately roughly L-shaped first reinforcing bar 10P' with the first wavy reinforcing bar 19A that extends in the longitudinal direction and exhibits a wavy shape, a stronger integration of the two can be achieved. Similarly, by connecting the second longitudinal bar 11B' of the roughly L-shaped second reinforcing bar 10B' and the separate second longitudinal bar 11Q' of the separately roughly L-shaped second reinforcing bar 10Q' with the second wavy reinforcing bar 19B that extends in the longitudinal direction and exhibits a wavy shape, a stronger integration of the two can be achieved. Furthermore, this configuration allows the first vertical reinforcement bars 11A', a separate first vertical reinforcement bar 11P', and the first corrugated reinforcement bars 19A between them, as well as the second vertical reinforcement bars 11B', a separate second vertical reinforcement bar 11Q', and the second corrugated reinforcement bars 19B between them, to resist, in the same manner as a truss beam, the pressure acting on the inside of the precast concrete slabs 20A' and 20B' when concrete is poured during the construction of the post-cast concrete body 70, and the earth pressure acting on the outside of the precast concrete slabs 20A and 20B when soil is backfilled before concrete is poured.

[0363] The above has described half-precast beams and their manufacturing methods that are applied to beams on the upper floors of buildings with reference to Figures 18 to 30. However, as shown in Figure 31, half-precast beams may also be applied to foundation beams of buildings. Here, Figures 31(a) and (b) are both longitudinal cross-sectional views perpendicular to the longitudinal direction, showing a pair of reinforced precast concrete slabs assembled, which constitute yet another example of a half-precast beam according to the second embodiment. Both show examples of a pair of reinforced precast concrete slabs 50M', 50N', which were described with reference to Figure 24, being applied to a foundation beam.

[0364] In the example shown in Figure 31(a), a leveling material (for example, crushed stone 95 or lean concrete 96) is laid on the excavated and prepared ground surface to ensure levelness. A pair of reinforced precast concrete slabs 50M' and 50N' are placed on top of the lean concrete 96, forming a gap G between them, and a steel beam 60 is placed in the center of the gap G. By pouring concrete into the gap G, a foundation beam, which is a half-precast beam (not shown), is fabricated.

[0365] On the other hand, the example shown in Figure 31(b) involves installing a precast concrete slab 20K' that also serves as a lower frame on top of crushed stone 95, and fitting the lower ends of a pair of reinforced precast concrete slabs 50M' and 50N' into a pair of recesses 25 provided on the upper surface of the precast concrete slab 20K'.

[0366] Since the lower end of the reinforced precast concrete slab 50M', 50N' is fitted into the recess 25 of the lower frame-type precast concrete slab 20K', it is possible to maintain a stable upright position of the reinforced precast concrete slab 50M', 50N' while eliminating the need for leveling material.

[0367] Other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

[0368] For example, as shown in Figure 32, in a configuration where the steel beam 60 is exposed in the central region of the beam, anchoring hardware 38 may be attached to the end of the upper main reinforcement 30 in the central region of the beam, and anchoring hardware 48 may be attached to the end of the lower main reinforcement 40 in the central region of the beam. Although not shown in the figure, in a configuration similar to Figure 32 where the steel beam 60 is exposed in the central region of the beam, concentrated reinforcing bars may be provided near both ends of the upper main reinforcement 30 and near both ends of the lower main reinforcement 40. [Explanation of Symbols]

[0369] 10A, 10C, 10E, 10G, 10H, 10I, 10K, 10M, 10N, 10A', 10E', 10F', 10G', 10H', 10M', 10N': First reinforcing muscle (reinforcing muscle) 10B, 10D, 10F, 10J, 10L, 10B', 10F': Secondary reinforcing muscles (reinforcing muscles) 10P, 10P': Additional primary reinforcement muscle (additional reinforcement muscle) 10Q,10Q': Additional second reinforcing muscle (additional reinforcing muscle) 11A, 11A': First vertical reinforcement (vertical reinforcement) 11B, 11B': Second vertical line (vertical line) 11P: Separate first vertical reinforcement (separate vertical reinforcement) 11Q: Separate second vertical reinforcement (separate vertical reinforcement) 12A, 12A': First transverse muscle (supertransverse muscle) 12B: Second superior transverse muscle (superior transverse muscle) 12P: Separate first upper transverse reinforcement (separate upper transverse reinforcement) 12Q: Separate second upper transverse reinforcement (separate upper transverse reinforcement) 13A, 13C, 13A': First upper hook (upper hook) 13B, 13D, 13B': Second upper hook (upper hook) 13a: Sections that bend and extend at a 90-degree angle. 14A: First lower transverse muscle (lower transverse muscle) 14B, 14B': Second inferior transverse muscle (inferior transverse muscle) 14P: Separate lower horizontal reinforcement (separate lower horizontal reinforcement) 14Q: Separate second lower transverse reinforcement (separate lower transverse reinforcement) 15A, 15A': First lower hook (lower hook) 15B, 15C, 15B': Second lower hook (lower hook) 15E, 15I': Long lower hook (1st long lower hook) 15F, 15J': Long lower hook (2nd long lower hook) 15a: Sections that bend and extend in a 90-degree direction 17: Planning 18A: First accessory muscle (accessory muscle) 18B: Second accessory muscle (accessory muscle) 19A: First wave-shaped reinforcing muscle (wave-shaped reinforcing muscle) 19B: Second wave-shaped reinforcing muscle (wave-shaped reinforcing muscle) 20A, 20C, 20E, 20G, 20I, 20E', 20G', 20I': First precast concrete slab (precast concrete slab) 20B, 20D, 20F, 20H, 20J, 20F', 20H', 20J': Second precast concrete slab (precast concrete slab) 20K: Precast concrete panel that also serves as a base frame. 22A, 22C, 22A': 1st vertical version (vertical version) 22B, 22D, 22B': 2nd vertical version (vertical version) 24A, 24A': First horizontal version (horizontal version) 24B: Second horizontal format (horizontal format) 25: Recess 26A, 27A, 27A': 1st lower horizontal version (lower horizontal version) 26B, 27B, 26B', 27B': 2nd lower horizontal version (lower horizontal version) 27a: Recess 28A: First upper recess 28B: Second upper recess 29A: First downward recess 29B: Second downward depression 30: Top main reinforcement 38: Fixing hardware 40: Bottom main reinforcement 48: Fixing hardware 50A, 50C, 50E, 50G, 50I, 50K, 50M, 50P, 50Q, 50R, 50T, 50V, 50W, 50A', 50C', 50E', 50G', 50K', 50M', 50P', 50Q', 50V', 50W', 50Y": First-generation reinforced precast concrete slab (reinforced precast concrete slab) 50B, 50D, 50F, 50H, 50J, 50L, 50N, 50S, 50U, 50X', 50B', 50D', 50F', 50H', 50L', 50N', 50X', 50Z', 50Z": Second-generation reinforced precast concrete slab (reinforced precast concrete slab) 50Y, 50Y': Third-generation reinforced precast concrete slab (reinforced precast concrete slab) 50Z, 50Z': 4th reinforced precast concrete slab (reinforced precast concrete slab) 60: Steel beam 70: Post-cast concrete body 70A: Concrete slab 91: Bottom frame 92: Floor frame 93: Floor line 95: Crushed stone (land leveling material) 96: Lean concrete (ground leveling material) 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 100I, 100', 100A', 100B', 100D', 100F', 100G', 100I': Half-precast beam G: Gap

Claims

1. A first reinforced precast concrete slab, comprising a plurality of first reinforcing bars, each having at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward, wherein each of the first longitudinal bars of the plurality of first reinforcing bars is embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars extending in the longitudinal direction are attached below the plurality of first upper transverse bars, The present invention comprises a second reinforced concrete slab, each of which has at least two second vertical bars, two second horizontal bars that bend at the lower end of the second vertical bars and extend laterally, and two second lower hooks that bend at the end of the second horizontal bars and extend upward, and each of the second vertical bars of the multiple second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main bar extending along the longitudinal direction is attached above the multiple second horizontal bars, A half-precast beam characterized in that the first precast concrete slab and the second precast concrete slab are arranged with a gap between them, a steel beam is arranged in the gap, and a post-cast concrete body is provided.

2. The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. The half-precast beam according to claim 1, characterized in that the first reinforced precast concrete slab and the second reinforced precast concrete slab are arranged with the gap between them, overlapping the first upper crossbar and the second upper crossbar, and overlapping the first lower crossbar and the second lower crossbar.

3. The first reinforcing bar has a substantially L-shape and further comprises a first lower hook that bends and extends from the lower end of the first longitudinal bar, and the first upper hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The second reinforcing bar has a substantially L-shape and further comprises a second upper hook that bends and extends from the upper end of the second longitudinal bar, and the second lower hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The half-precast beam according to claim 1, characterized in that the first reinforced precast concrete slab and the second reinforced precast concrete slab are arranged with the gap between them, with the first upper horizontal reinforcement and the second upper hook intersecting, and the second lower horizontal reinforcement and the first lower hook intersecting.

4. Of the upper end main reinforcements attached to the first upper transverse reinforcement and the second upper transverse reinforcement, the upper end main reinforcement positioned at the overlapping position of the first upper transverse reinforcement and the second upper transverse reinforcement is attached below only one of the first upper transverse reinforcement and the second upper transverse reinforcement, and not below the other. Of the lower end main reinforcements attached to the first lower transverse reinforcement and the second lower transverse reinforcement, the lower end main reinforcement positioned at the overlapping position of the first lower transverse reinforcement and the second lower transverse reinforcement is attached above only one of the first lower transverse reinforcement and the second lower transverse reinforcement, and not above the other. The half-precast beam according to claim 2, characterized in that when the first upper transverse reinforcement and the second upper transverse reinforcement are overlapped, and the first lower transverse reinforcement and the second lower transverse reinforcement are overlapped, the multiple upper main reinforcement bars are arranged laterally at equal or approximately equal intervals, and the multiple lower main reinforcement bars are arranged laterally at equal or approximately equal intervals.

5. With respect to the first precast concrete slab, at least some of the upper main reinforcement bars of the plurality of upper main reinforcement bars are embedded, The half-precast beam according to claim 2 or 3, characterized in that at least some of the lower main reinforcements among the plurality of lower main reinforcements are embedded in the second precast concrete slab.

6. The first precast concrete slab comprises at least a first vertical slab extending in the vertical direction and a first upper horizontal slab extending horizontally from the upper end of the first vertical slab. The second precast concrete slab comprises at least a second vertical slab extending in the vertical direction and a second lower horizontal slab extending horizontally from the lower end of the second vertical slab, The half-precast beam according to claim 2 or 3, characterized in that some of the upper main reinforcement bars of the plurality of upper main reinforcement bars are embedded in the first upper horizontal plate, and some of the lower main reinforcement bars of the plurality of lower main reinforcement bars are embedded in the second lower horizontal plate.

7. The first precast concrete slab comprises a first vertical slab extending in the vertical direction and a first lower horizontal slab extending horizontally from the lower end of the first vertical slab. The second precast concrete slab comprises a second vertical slab extending in the vertical direction and a second lower horizontal slab extending horizontally from the lower end of the second vertical slab. At least a plurality of the lower end main reinforcements are embedded in the second lower horizontal plate, The half-precast beam according to claim 2 or 3, characterized in that the end faces of the first lower cross plate and the second lower cross plate are in contact with each other.

8. The first precast concrete slab comprises a first vertical slab extending in the vertical direction, The second precast concrete slab comprises a second vertical slab extending in the vertical direction, A first upper recess and a first lower recess are provided on the inner side of the upper and lower ends of the first vertical plate, respectively. The half-precast beam according to claim 2 or 3, characterized in that a second upper recess and a second lower recess are provided on the inner side of the upper and lower ends of the second vertical plate, respectively.

9. A plurality of first reinforcing bars are provided, each comprising at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward. It comprises a plurality of separate first reinforcing bars, each comprising at least a separate first vertical bar and a separate first upper transverse bar that bends at the upper end of the separate first vertical bar and extends laterally. Each of the aforementioned separate first reinforcing bars is embedded at intervals along the longitudinal direction of the first precast concrete slab. Each of the aforementioned separate first reinforcing bars is arranged to overlap the aforementioned separate first upper transverse bar of the aforementioned first reinforcing bar, and then tied or welded together. A precast concrete slab with third reinforcement bars, wherein the upper main reinforcement bars extending in the longitudinal direction are attached below a plurality of the first upper transverse reinforcements, The device comprises a plurality of second reinforcing bars, each having at least a second longitudinal bar, a second lower transverse bar that bends at the lower end of the second longitudinal bar and extends laterally, and a second lower hook that bends at the end of the second lower transverse bar and extends upward. It comprises a plurality of separate second reinforcing bars, each comprising at least a separate second vertical bar and a separate second lower transverse bar that bends at the lower end of the separate second vertical bar and extends laterally. Each of the aforementioned separate second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab. The second lower transverse bar of the corresponding second reinforcing bar is arranged to overlap with the second lower transverse bar of each of the aforementioned separate second reinforcing bars, and is then tied or welded together. It comprises a precast concrete slab with a fourth reinforced concrete slab, to which the longitudinally extending lower end main reinforcement is attached above a plurality of the second lower transverse reinforcements, A half-precast beam characterized in that the first precast concrete slab and the second precast concrete slab are arranged with a gap between them, a steel beam is arranged in the gap, and a post-cast concrete body is provided.

10. The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. The half-precast beam according to claim 9, characterized in that the third reinforced precast concrete slab and the fourth reinforced precast concrete slab are arranged with the gap between them, overlapping the first upper crossbar and the second upper crossbar, and overlapping the first lower crossbar and the second lower crossbar.

11. The first vertical reinforcement has a substantially L-shape, further comprising a first lower hook that bends and extends from the lower end of the first vertical reinforcement, and the first upper hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The second longitudinal reinforcement has a substantially L-shape, further comprising a second upper hook that bends and extends from the upper end of the second longitudinal reinforcement, and the second lower hook is a 90-degree hook, a 135-degree hook, or a 180-degree hook. The half-precast beam according to claim 9, characterized in that the third reinforced precast concrete slab and the fourth reinforced precast concrete slab are arranged with the gap between them, with the first upper horizontal reinforcement and the second upper hook intersecting, and the second lower horizontal reinforcement and the first lower hook intersecting.

12. In the longitudinal direction, a first reinforcing bar is arranged between the first reinforcing bars that are tied or welded to the other first reinforcing bar, and the other first reinforcing bar is not present between them. The half-precast beam according to claim 9, characterized in that, in the longitudinal direction, the second reinforcing bar is arranged between the second reinforcing bars that are tied or welded to the other second reinforcing bar, and there is no counterpart second reinforcing bar present.

13. Multiple upper main reinforcement bars are provided in multiple stages, and each stage contains multiple upper main reinforcement bars. The half-precast beam according to claim 1 or 9, characterized in that multiple stages of lower main reinforcement are provided, and each stage contains multiple lower main reinforcement bars.

14. The first auxiliary reinforcement, which prevents the sagging or swaying of the first upper transverse reinforcement to which the upper main reinforcement is attached, is arranged so as to straddle the first upper transverse reinforcement and the first vertical reinforcement. The half-precast beam according to claim 13, characterized in that a second auxiliary reinforcement, which prevents the sagging or swaying of the second lower horizontal reinforcement to which the lower main reinforcement is attached, is arranged so as to span from the second lower horizontal reinforcement to the second vertical reinforcement.

15. The half-precast beam according to claim 13, characterized in that, among the plurality of first and second reinforcing bars arranged in the longitudinal direction, some of the first and second reinforcing bars have relatively large cross-sectional diameters, and these large-diameter reinforcing bars prevent both the first upper transverse bar and the second lower transverse bar from sagging or swaying.

16. One of the first upper hook and the second upper hook is a 90-degree hook or a 135-degree hook, and the other is a 135-degree hook. The half-precast beam according to claim 2 or 10, characterized in that one of the first lower hook and the second lower hook is a 90-degree hook or a 135-degree hook, and the other is a 135-degree hook.

17. A first reinforced precast concrete slab, comprising a plurality of first reinforcing bars, each having at least a first longitudinal bar, a first upper transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, and a first upper hook that bends at the end of the first upper transverse bar and extends downward, wherein each of the first longitudinal bars of the plurality of first reinforcing bars is embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars extending in the longitudinal direction are attached below the plurality of first upper transverse bars, A precast concrete slab with second reinforcing bars is prepared, and a steel beam is prepared, wherein each of the second vertical bars of a plurality of second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a second main reinforcement extending along the longitudinal direction is attached above the plurality of second horizontal bars. Position the first reinforced precast concrete slab, arrange the steel beam inside the first reinforced precast concrete slab, move the second reinforced precast concrete slab to position it with a gap between the first and second precast concrete slabs, and move and position the steel beam in the center of the gap. A method for manufacturing a half-precast beam, characterized by producing a half-precast beam by pouring concrete into the gap to form a post-cast concrete body.

18. The first reinforcing bar has a C-shape, further comprising a first lower transverse bar that bends at the lower end of the first longitudinal bar and extends laterally, and a first lower hook that bends at the end of the first lower transverse bar and extends upward, and a plurality of lower main bars extending in the longitudinal direction are attached above the first lower transverse bars. The second reinforcing bar has a C-shape, further comprising a second upper transverse bar that bends at the upper end of the second longitudinal bar and extends laterally, and a second upper hook that bends at the end of the second upper transverse bar and extends downward, and a plurality of upper main bars extending in the longitudinal direction are attached below the second upper transverse bars. Of the upper end main reinforcements attached to the first upper transverse reinforcement and the second upper transverse reinforcement, the upper end main reinforcement positioned at the overlapping position of the first upper transverse reinforcement and the second upper transverse reinforcement is attached below only one of the first upper transverse reinforcement and the second upper transverse reinforcement, and not below the other. Of the lower end main reinforcements attached to the first lower transverse reinforcement and the second lower transverse reinforcement, the lower end main reinforcement positioned at the overlapping position of the first lower transverse reinforcement and the second lower transverse reinforcement is attached above only one of the first lower transverse reinforcement and the second lower transverse reinforcement, and not above the other. A method for manufacturing a half-precast beam according to claim 17, characterized in that the first upper transverse reinforcement and the second upper transverse reinforcement overlap, and the first lower transverse reinforcement and the second lower transverse reinforcement overlap, thereby arranging a plurality of upper main reinforcement bars at equal or approximately equal intervals in the lateral direction, and arranging a plurality of lower main reinforcement bars at equal or approximately equal intervals in the lateral direction.

19. The first precast concrete slab comprises at least a first vertical slab extending in the vertical direction and a first lower horizontal slab extending horizontally from the lower end of the first vertical slab. The second precast concrete slab comprises at least a second vertical slab extending in the vertical direction and a second lower horizontal slab extending horizontally from the lower end of the second vertical slab, Multiple lower end main reinforcements are embedded in the second lower horizontal plate. By bringing the end faces of the first lower horizontal plate and the second lower horizontal plate into contact with each other, the first vertical plate and the second vertical plate, along with the first lower horizontal plate and the second lower horizontal plate, form a U-shaped formwork with a cross-sectional shape perpendicular to the longitudinal direction that opens upward. A method for manufacturing a half-precast beam according to claim 17, characterized in that concrete is poured into the formwork to form the post-cast concrete body.

20. The first vertical reinforcement further comprises a first upper hook and a first lower hook, The aforementioned second vertical reinforcement further comprises a second upper hook and a second lower hook, At least one of the first lower hooks of the multiple first reinforcing bars in the first reinforced precast concrete slab, which is positioned first, is a long lower hook, longer than the length of all the second upper hooks of the second reinforcing bars in the second reinforced precast concrete slab, which is positioned second. When lowering the second reinforced precast concrete slab downwards, the long lower hook is passed in advance between the multiple second lower hooks provided on the second reinforced precast concrete slab, or At least one of the second upper hooks of the multiple second reinforcing bars provided in the second reinforced precast concrete slab, which is positioned later, is an elongated upper hook, longer than the length of all the first lower hooks of the first reinforcing bars provided in the first reinforced precast concrete slab, which is positioned earlier. The method for manufacturing a half-precast beam according to claim 17, characterized in that when lowering the second reinforced precast concrete slab downward, the long upper hook is passed in advance between the plurality of first upper hooks provided on the first reinforced precast concrete slab.

21. In the configuration having the long lower hook, of the two first reinforcing bars located at both ends in the longitudinal direction of the first precast concrete slab, the first lower hook of one of the first reinforcing bars is the longest first long lower hook, and the first lower hook of the other first reinforcing bar is the next longest second long lower hook. After passing the first long lower hook through the multiple second lower hooks provided on the second reinforced precast concrete slab, then pass the second long lower hook through the multiple second lower hooks provided on the second reinforced precast concrete slab, or In the configuration having the long upper hook, of the two second reinforcing bars located at both ends in the longitudinal direction of the second precast concrete slab, the second upper hook of one of the second reinforcing bars is the longest first long upper hook, and the second upper hook of the other second reinforcing bar is the next longest second long upper hook. A method for manufacturing a half-precast beam according to claim 20, characterized in that the first long upper hook is passed first between the plurality of first upper hooks provided on the first reinforced precast concrete slab, and then the second long upper hook is passed between the plurality of first upper hooks provided on the first reinforced precast concrete slab.

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