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] A half-precast beam 100 is formed having a pair of first reinforced precast concrete slabs 60 and a second reinforced precast concrete slab 60A, wherein the pair of first precast concrete slabs 20 are arranged with a gap G between them, with the first horizontal reinforcement 12 and the first upper hook 13 intersecting, and the pair of first reinforced precast concrete slabs 60 are arranged above the second reinforced precast concrete slab 60A, with the first lower hook 15 and the second upper hook 13A intersecting, and a post-cast concrete body 70 is provided in the gap G.

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 beams on the upper floors and foundation beams made of RC (Reinforced Concrete) in a building (hereinafter referred to as reinforced concrete beams) on site, in order to save labor in installing temporary members and improve workability, as a measure, 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] In this way, 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-manufactured, 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.

[0004] Furthermore, in the case of so-called full precast beams, where the entire reinforced concrete beam is formed from precast concrete panels, the weight becomes heavy, reducing transportability, and construction costs tend to increase because large-capacity lifting equipment is required during construction. However, these problems can be resolved by applying half-precast beams.

[0005] 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]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-79695 [Overview of the project] [Problems that the invention aims to solve]

[0007] 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.

[0008] 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.

[0009] 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]

[0010] To achieve the above objective, one embodiment of the half-precast beam according to the present invention is: A pair of precast concrete slabs with first reinforcing bars, each of which has a first longitudinal bar, a first transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, a first upper hook that bends at the end of the first transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first longitudinal bar and extends upward, forming a roughly L-shape, the first longitudinal bars of each of the multiple first reinforcing bars are embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars that extend in the longitudinal direction are attached below the multiple first transverse bars, The second reinforced concrete slab comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second reinforcing bars, each having a substantially U-shape formed by a series of second upper hooks that bend at the ends of each of the second longitudinal bars, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks that bend upward, each of which is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main reinforcement extending along the longitudinal direction is attached above the plurality of second transverse bars and embedded in the second precast concrete slab, The pair of first precast concrete slabs are arranged with a gap between them, with the first horizontal reinforcement and the first upper hook intersecting, and the pair of first precast concrete slabs are arranged above the second reinforced precast concrete slab, with the first lower hook and the second upper hook intersecting, and a post-cast concrete body is provided in the gap.

[0011] According to this embodiment, a pair of precast concrete slabs with first reinforcement bars, each having embedded first vertical bars constituting a plurality of roughly L-shaped first reinforcing bars and upper main bars attached below the plurality of first horizontal bars, are arranged with a gap between them, with the first horizontal bars and first upper hooks of both slabs intersecting. In addition, a precast concrete slab with second reinforcement bars, each having embedded second horizontal bars constituting a plurality of roughly U-shaped second reinforcing bars and lower main bars attached above the plurality of second horizontal bars, is arranged above it with the first lower hooks and second upper hooks intersecting, and a post-cast concrete body is provided in the gap. As a result, when the pair of precast concrete slabs with first and second reinforcement bars are installed, the beam reinforcement is automatically arranged. This makes it possible to reduce the labor involved in setting up and removing formwork using the pair of precast concrete slabs with first and second reinforcement bars, eliminate or reduce the labor involved in arranging the beam reinforcement, and ensure quality because it is factory-made.

[0012] Furthermore, by intersecting the first transverse reinforcement and the first upper hook of both of the pair of first reinforced precast concrete slabs, and by intersecting the first lower hook and the second upper hook 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 ensures ductility by providing a sufficient restraint area.

[0013] Here, "approximately L-shaped" refers to a configuration in which 90-degree hooks, 135-degree hooks, or 180-degree hooks are provided at both ends of an L-shaped reinforcing bar consisting of a first vertical bar and a first horizontal bar.

[0014] 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. Similarly, even in 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.

[0015] Furthermore, other embodiments of the half-precast beam according to the present invention include: The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, The second reinforced concrete slab comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second reinforcing bars, each having a substantially U-shape formed by a series of second upper hooks that bend at the ends of each of the second longitudinal bars, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks that bend upward, each of which is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main reinforcement extending along the longitudinal direction is attached above the plurality of second transverse bars and embedded in the second precast concrete slab, The pair of third precast concrete slabs are arranged with a gap between them, with the third horizontal reinforcement and the third upper hook intersecting, and the pair of third precast concrete slabs are arranged above the second reinforced precast concrete slab, with the third lower hook and the second upper hook intersecting, and a post-cast concrete body is provided in the gap.

[0016] According to this embodiment, at least one of the separate third vertical bars of each of the multiple separate third reinforcing bars, each connected to a separate third vertical bar and a corrugated reinforcing bar (truss bar), or each of the multiple separate third reinforcing bars, each connected to a pair of separate third vertical bars and a corrugated reinforcing bar (truss bar), is embedded at intervals in the longitudinal direction of the third precast concrete slab, and the third vertical bars of the third reinforcing bars, which are roughly L-shaped and corresponding to each corrugated reinforcing bar and the separate third vertical bar, are tied or welded together, and the upper main bars are attached below the first transverse bars of the multiple first reinforcing bars, forming a pair of third reinforced concrete slabs. The Reet slab is positioned with a gap between it and the third horizontal bars and third upper hooks on both sides intersecting, and the second horizontal bars that make up the multiple second reinforcing bars forming a roughly U-shape that opens upwards are embedded, and the lower end main bars are attached above the multiple second horizontal bars. Above the second reinforced precast concrete slab, the third lower hook and second upper hook are positioned while intersecting, and a post-cast concrete body is provided in the gap, so that when a pair of third reinforced precast concrete slabs and second reinforced precast concrete slabs are installed, the beam reinforcement is automatically arranged. As a result, the labor of setting up and removing formwork is reduced by using a pair of third and second precast concrete slabs, the work of arranging the beam reinforcement can be eliminated or reduced, and quality can be ensured because it is factory manufactured.

[0017] Furthermore, by embedding the entire L-shaped third reinforcing bar, which is tied or otherwise secured to the third precast concrete slab, into the later-cast concrete body, the shear reinforcement effect can be enhanced. As a result, even if the degree of integration between the third precast concrete slab and the later-cast concrete body is not good, a high shear reinforcement effect can be achieved by the L-shaped third reinforcing bar.

[0018] In addition, when placing concrete during the construction of the later-placed concrete body, with respect to the pressure acting on the inner side of the precast concrete slab when placing the concrete, or the earth pressure acting when backfilling the earth acting on the outer side of the precast concrete slab before placing the concrete, etc., the third longitudinal reinforcement, a separate third longitudinal reinforcement, and the corrugated reinforcement between them can resist in the same mechanism as the truss beam.

[0019] Furthermore, by crossing the third horizontal reinforcements and the third upper hooks on both sides of the pair of precast concrete slabs with third reinforcing bars, and crossing the third lower hooks and the second upper hooks on both sides of each precast concrete slab with third reinforcing bars and the precast concrete slab with second reinforcing bars, a half-precast beam can be formed that has high torsional strength and can ensure toughness performance because a sufficient restraint area can be expected.

[0020] Here, "at least the separate third longitudinal reinforcement of the separate third reinforcement is embedded in the third precast concrete slab" means that it includes a form in which only the separate third longitudinal reinforcement is embedded in the third precast concrete slab and a form in which a part of the corrugated reinforcement is embedded in addition to the separate third longitudinal reinforcement.

[0021] In addition, another aspect of the half-precast beam according to the present invention is a first longitudinal reinforcement, a first horizontal reinforcement that bends at the upper end of the first longitudinal reinforcement and extends in the lateral direction, a first upper hook that is a 90-degree hook, a 135-degree hook, or a 180-degree hook that bends and extends at the end of the first horizontal reinforcement, and a first lower hook that bends at the lower end of the first longitudinal reinforcement and extends upward are continuously arranged in a substantially L shape. Each of the first longitudinal reinforcements of a plurality of first reinforcements is embedded at intervals in the longitudinal direction of the first precast concrete slab, and an upper main reinforcement extending in the longitudinal direction is attached below the plurality of first horizontal reinforcements. A pair of precast concrete slabs with first reinforcing bars, The concrete slab for cast-in-place pressure-resistant slabs has a plurality of second reinforcing bars, each of which is embedded at intervals in the concrete slab for cast-in-place pressure-resistant slabs, and each of which is embedded above the plurality of second reinforcing bars, the concrete slab for cast-in-place pressure-resistant slabs has a plurality of lower main reinforcing bars arranged above the plurality of second reinforcing bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, and a plurality of lower main reinforcing bars are arranged above the plurality of second reinforcing bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, and The pair of first precast concrete slabs are arranged with a gap between them, with the corresponding first upper hooks of each slab crossing, and the pair of first precast concrete slabs are arranged above the reinforced concrete slab with a gap between them, with the first lower hooks of the pair of first precast concrete slabs crossing the second upper hooks of the reinforced concrete slab with a gap between them, and a post-cast concrete body is provided in the gap.

[0022] According to this aspect, each first vertical bar constituting a plurality of first reinforcing bars having a substantially L shape is embedded, and an upper end main bar is attached below a plurality of first horizontal bars. A pair of precast concrete slabs with first reinforcing bars are arranged with a gap while crossing both first horizontal bars and first upper hooks, and each second horizontal bar constituting a plurality of second reinforcing bars having a substantially U shape opened upward is embedded, and a lower end main bar is attached above the plurality of second horizontal bars. Above the concrete slab for a cast-in-place pressure-resistant slab with reinforcing bars, it is arranged while crossing a first lower hook and a second upper hook, and a post-cast concrete body is provided in the gap. When a pair of precast concrete slabs with first reinforcing bars are installed on the cast-in-place pressure-resistant slab with reinforcing bars constructed (manufactured), the reinforcement of the beam bars is automatically performed. As a result, while achieving labor saving in the installation and demolding of the formwork by the pair of first precast concrete slabs and the cast-in-place pressure-resistant slab with reinforcing bars, the reinforcement work of the beam bars can be eliminated or labor-saving, and since the precast concrete slab with first reinforcing bars is factory-produced, quality assurance can be achieved.

[0023] Also, by crossing the first horizontal bars and the first upper hooks of both of the pair of precast concrete slabs with first reinforcing bars, and crossing the first lower hooks and the second upper hooks of both of each precast concrete slab with first reinforcing bars and the cast-in-place pressure-resistant slab with reinforcing bars, a half-precast beam having high torsional strength and capable of ensuring toughness performance because a sufficient restraint region can be expected can be formed.

[0024] Another aspect of the half-precast beam according to the present invention is a plurality of third reinforcing bars including a third vertical bar, a third horizontal bar that bends at the upper end of the third vertical bar and extends horizontally, a third upper hook that is a 90-degree hook, a 135-degree hook, or a 180-degree hook that bends and extends at the end of the third horizontal bar, and a third lower hook that bends at the lower end of the third vertical bar and extends upward, continuously presenting a substantially L shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, The concrete slab for cast-in-place pressure-resistant slabs has a plurality of second reinforcing bars, each of which is embedded at intervals in the concrete slab for cast-in-place pressure-resistant slabs, and each of which is embedded above the plurality of second reinforcing bars, the concrete slab for cast-in-place pressure-resistant slabs has a plurality of lower main reinforcing bars arranged above the plurality of second reinforcing bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, and a plurality of lower main reinforcing bars are arranged above the plurality of second reinforcing bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, and The pair of third precast concrete slabs are arranged with a gap between them, with the corresponding third upper hooks of each slab crossing, and the pair of third precast concrete slabs are arranged above the reinforced concrete slab with a gap between them, with the third lower hooks of each slab crossing the second upper hooks of the reinforced concrete slab with a gap between them, and a post-cast concrete body is provided in the gap.

[0025] According to this embodiment, at least one of the separate third longitudinal bars of each of the multiple separate third reinforcing bars, each connected to a separate third longitudinal bar and a corrugated reinforcing bar (truss bar), or each of the multiple separate third reinforcing bars, each connected to a pair of separate third longitudinal bars and a corrugated reinforcing bar (truss bar), is embedded at intervals in the longitudinal direction of the third precast concrete slab, and the third longitudinal bars of the third reinforcing bars, which are roughly L-shaped and corresponding to each corrugated reinforcing bar and the separate third longitudinal bar, are tied or welded together, and the upper main bars are attached below the first transverse bars of the multiple first reinforcing bars, forming a pair of third reinforcing bars attached to the precast concrete slab. The concrete slab is positioned with a gap between it and the third horizontal bars and third upper hooks on both sides, and the second horizontal bars that make up the multiple second reinforcing bars forming a roughly U-shape that opens upwards are embedded in it, and the lower end main bars are attached above the multiple second horizontal bars. The third lower hook and second upper hook are positioned above the concrete slab for the cast-in-place pressure slab, and a post-cast concrete body is provided in the gap, so that the beam reinforcement is automatically arranged when the pair of precast concrete slabs with third reinforcement and the concrete slab for the cast-in-place pressure slab are installed. As a result, the labor of setting up and removing formwork is reduced by the pair of precast concrete slabs with third reinforcement and the concrete slab for the cast-in-place pressure slab, and the work of arranging the beam reinforcement can be eliminated or reduced. Furthermore, quality can be ensured because it is manufactured in a factory.

[0026] Furthermore, by embedding the entire L-shaped third reinforcing bar, which is tied or otherwise secured to the third precast concrete slab, into the later-cast concrete body, the shear reinforcement effect can be enhanced. As a result, even if the degree of integration between the third precast concrete slab and the later-cast concrete body is not good, a high shear reinforcement effect can be achieved by the L-shaped third reinforcing bar.

[0027] Furthermore, when constructing a post-cast concrete body, the third longitudinal reinforcement, separate third longitudinal reinforcement, and the corrugated reinforcement between them can resist the pressure acting on the inside of the precast concrete slab when concrete is poured, as well as the earth pressure acting on the outside of the precast concrete slab when soil is backfilled before concrete is poured, in a mechanism similar to that of a truss beam.

[0028] Furthermore, by intersecting the third horizontal reinforcement and the third upper hook of both of the pair of precast concrete slabs with third reinforcement, and by intersecting the third lower hook and the second upper hook of both the precast concrete slab with third reinforcement and the cast-in-place pressure-resistant concrete slab, a half-precast beam can be formed that has high torsional strength and ensures ductility by providing a sufficient restraining area.

[0029] Furthermore, other embodiments of the half-precast beam according to the present invention include: The present invention is characterized in that a steel beam is embedded in the aforementioned post-cast concrete body.

[0030] According to this embodiment, by embedding a steel beam in a post-cast concrete body, a high-strength and high-rigidity half-precast beam made of SRC (Steel Reinforced Concrete) can be formed.

[0031] Furthermore, one embodiment of the method for manufacturing a half-precast beam according to the present invention is: A pair of precast concrete slabs with first reinforcing bars, each of which has a first longitudinal bar, a first transverse bar that bends at the upper end of the first longitudinal bar and extends laterally, a first upper hook that bends at the end of the first transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first longitudinal bar and extends upward, forming a roughly L-shape, the first longitudinal bars of each of the multiple first reinforcing bars are embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars that extend in the longitudinal direction are attached below the multiple first transverse bars, A precast concrete slab with second reinforcing bars is prepared, in which each of the second reinforcing bars of the second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second reinforcing bars and embedded in the second precast concrete slab, and the second transverse bars of the second reinforcing bars are embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second transverse bars. Position the second reinforced precast concrete slab, Move one of the first reinforced precast concrete slabs so that the first lower hooks of each of the multiple first reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars. The other precast concrete slab with reinforced steel is moved so that the corresponding first upper hooks of both precast concrete slabs with reinforced steel are crossed, and a gap is created between the two precast concrete slabs with reinforced steel to position it. A formwork is installed to close the gap between the upper surface of the second reinforced precast concrete slab and the lower surface of the first reinforced precast concrete slab. The method is characterized by producing a half-precast beam by pouring concrete into the aforementioned gap to form a post-cast concrete body.

[0032] According to this embodiment, the second reinforced precast concrete slab is positioned, one of the first reinforced precast concrete slabs is moved so that the first lower hooks of each of the multiple first reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars, the other first reinforced precast concrete slab is moved so that the corresponding first upper hooks of both first reinforced precast concrete slabs intersect, a gap is left between the two first reinforced precast concrete slabs, a formwork is installed to close the gap between the upper surface of the second reinforced precast concrete slab and the lower surface of the first reinforced precast concrete slab, and concrete is poured into the gap to form a post-cast concrete body, thereby automatically arranging the beam reinforcement when the pair of first reinforced precast concrete slabs and second reinforced precast concrete slabs are installed. This design allows for labor savings in formwork installation and removal using a pair of first and second precast concrete panels, while also eliminating or streamlining the reinforcement work for beams. Furthermore, because the structure is manufactured in a factory, quality can be ensured.

[0033] Furthermore, another aspect of the method for manufacturing a half-precast beam according to the present invention is: The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, A precast concrete slab with second reinforcing bars is prepared, in which each of the second reinforcing bars of the second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second reinforcing bars and embedded in the second precast concrete slab, and the second transverse bars of the second reinforcing bars are embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second transverse bars. Position the second reinforced precast concrete slab, Move one of the precast concrete slabs with the third reinforcement bars so that the third lower hooks of each of the multiple third reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars. The other precast concrete slab with the third reinforcement is moved so that the corresponding third upper hooks of both precast concrete slabs with the third reinforcement intersect, and a gap is created between the two precast concrete slabs with the third reinforcement to position it. The method is characterized by producing a half-precast beam by pouring concrete into the aforementioned gap to form a post-cast concrete body.

[0034] According to this embodiment, the second reinforced precast concrete slab is positioned, one of the third reinforced precast concrete slabs is moved so that the third lower hooks of each of the multiple third reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars, the other reinforced precast concrete slab is moved so that the corresponding third upper hooks of both reinforced precast concrete slabs intersect, a gap is left between the two reinforced precast concrete slabs, and concrete is poured into the gap to form a post-cast concrete body and manufacture a half-precast beam. In this way, when a pair of reinforced precast concrete slabs and second reinforced precast concrete slabs are installed, the reinforcement of the beam is automatically arranged. As a result, the labor of setting up and removing formwork is reduced by using a pair of third and second precast concrete slabs, the work of arranging the beam reinforcement can be eliminated or reduced, and quality can be ensured because it is manufactured in a factory.

[0035] Furthermore, another aspect of the method for manufacturing a half-precast beam according to the present invention is: Prepare a pair of precast concrete slabs with first reinforcing bars, each of which consists of a first vertical bar, a first horizontal bar that bends at the upper end of the first vertical bar and extends laterally, a first upper hook that bends at the end of the first horizontal bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first vertical bar and extends upward, forming a roughly L-shape. Each of the first vertical bars of the 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 multiple first horizontal bars. Multiple second reinforcing bars are arranged, each consisting of a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and second upper hooks, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks, bending at the ends of each of the second longitudinal bars, forming a roughly U-shape that opens upward in a continuous manner, and multiple lower main bars are arranged above the multiple second transverse bars. A concrete slab for a cast-in-place pressure-resistant slab is fabricated by pouring concrete so as to embed multiple second horizontal reinforcements and the lower main reinforcements. While crossing the first lower hooks of the pair of first precast concrete slabs and the corresponding second upper hooks of the cast-in-place pressure-resistant concrete slab, the pair of first precast concrete slabs are positioned above the cast-in-place pressure-resistant concrete slab with a gap between them. A formwork is installed to close the gap between the upper surface of the cast-in-place pressure-resistant concrete slab and the lower surface of the first reinforced precast concrete slab. The method is characterized by producing a half-precast beam by pouring concrete into the aforementioned gap to form a post-cast concrete body.

[0036] According to this embodiment, a concrete slab for cast-in-place pressure slabs is manufactured, and the pair of first precast concrete slabs are positioned above the cast-in-place pressure slab with a gap between them, while crossing the first lower hooks of the pair of first precast concrete slabs with the corresponding second upper hooks of the cast-in-place pressure slab concrete slabs. A formwork is then installed to close the gap between the upper surface of the cast-in-place pressure slab concrete slab and the lower surface of the first reinforced precast concrete slab, and concrete is poured into the gap to form a post-cast concrete body. As a result, when the pair of first reinforced precast concrete slabs are installed on top of the constructed (manufactured) reinforced cast-in-place pressure slab concrete slab, the beam reinforcement is automatically arranged. This makes it possible to reduce the labor involved in setting up and removing formwork using the pair of first precast concrete slabs and the reinforced cast-in-place pressure slab concrete slab, while eliminating or reducing the labor involved in arranging the beam reinforcement. Furthermore, since the first reinforced precast concrete slab is factory-made, quality can be ensured.

[0037] Furthermore, another aspect of the method for manufacturing a half-precast beam according to the present invention is: The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars are prepared, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars. Multiple second reinforcing bars are arranged, each consisting of a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and second upper hooks, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks, bending at the ends of each of the second longitudinal bars, forming a roughly U-shape that opens upward in a continuous manner, and multiple lower main bars are arranged above the multiple second transverse bars. A concrete slab for a cast-in-place pressure-resistant slab is fabricated by pouring concrete so as to embed multiple second horizontal reinforcements and the lower main reinforcements. While crossing the third lower hooks of the pair of third precast concrete slabs and the corresponding second upper hooks of the cast-in-place pressure-resistant concrete slab, the pair of third precast concrete slabs are positioned above the cast-in-place pressure-resistant concrete slab with a gap between them. The method is characterized by producing a half-precast beam by pouring concrete into the aforementioned gap to form a post-cast concrete body.

[0038] According to this embodiment, a concrete slab for cast-in-place pressure-resistant slabs is manufactured, and the pair of third precast concrete slabs are positioned above the cast-in-place pressure-resistant slab with a gap between them, while crossing the third lower hooks of the third precast concrete slabs with the corresponding second upper hooks of the cast-in-place pressure-resistant slab. Concrete is then poured into the gap to form a cast-in-place concrete body. As a result, when the pair of third precast concrete slabs with reinforcement and the cast-in-place pressure-resistant slab are installed, the reinforcement of the beams is automatically arranged. This makes it possible to reduce the labor involved in setting up and removing formwork using the pair of third precast concrete slabs and the cast-in-place pressure-resistant slab, eliminate or reduce the labor involved in arranging the reinforcement of the beams, and ensure quality because it is manufactured in a factory.

[0039] Furthermore, another aspect of the method for manufacturing a half-precast beam according to the present invention is: Further steel beams were prepared, The method is characterized by positioning the steel beam in the gap and then pouring concrete to form the post-cast concrete body.

[0040] According to this embodiment, a high-strength and high-rigidity half-precast beam made of SRC can be formed by positioning a steel beam in the gap and then pouring concrete to form a post-cast concrete body. [Effects of the Invention]

[0041] 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]

[0042] [Figure 1]This is a perspective view of a pair of first reinforced precast concrete slabs and second reinforced precast concrete slabs that constitute an example of a half-precast beam according to the embodiment. [Figure 2] Figures (a) to (d) are process diagrams of the manufacturing method for an example of a half-precast beam according to the 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 embodiment. [Figure 3] (a) to (c) are diagrams showing the process of manufacturing another example of a half-precast beam according to the embodiment, along with a longitudinal section view perpendicular to the longitudinal direction of the other example of a half-precast beam according to the embodiment. [Figure 4] Figures (a) to (e) are process diagrams of a manufacturing method for yet another example of the half-precast beam according to the embodiment, and each diagram shows a longitudinal section of the yet another example of the half-precast beam according to the embodiment perpendicular to the longitudinal direction. [Figure 5] Figures (a) to (d) are process diagrams of a manufacturing method for yet another example of the half-precast beam according to the embodiment, and each diagram shows a longitudinal section of the yet another example of the half-precast beam according to the embodiment perpendicular to the longitudinal direction. [Modes for carrying out the invention]

[0043] Hereinafter, an example of a half-precast beam and its manufacturing method according to the 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.

[0044] [Half-precast beam according to an embodiment and its manufacturing method] Referring to Figures 1 to 5, several examples of the half-precast beam and its manufacturing method according to the embodiment will be described. Here, Figure 1 is a perspective view of a pair of first reinforced precast concrete slabs and second reinforced precast concrete slabs that constitute an example of the half-precast beam according to the embodiment. Figure 2 is a process diagram of the manufacturing method of an example of the half-precast beam according to the embodiment, in the order of (a) to (d), and shows a longitudinal cross-sectional view perpendicular to the longitudinal direction of the example of the half-precast beam according to the embodiment.

[0045] The half-precast beam 100 shown in Figure 2(d) has a pair of first reinforced precast concrete slabs 60 arranged with a gap G between them, a second reinforced precast concrete slab 60A located below them, and a post-cast concrete body 70 provided in the gap G.

[0046] As shown in Figure 1, the first reinforced precast concrete slab 60 is formed by attaching a plurality of first reinforcing bars 10 to the first precast concrete slab 20 at intervals along its longitudinal direction.

[0047] On the other hand, the second reinforced precast concrete slab 60A is formed by attaching multiple second reinforcing bars 10A to the second precast concrete slab 40 at intervals along its longitudinal direction.

[0048] The first reinforcing bar 10 consists of a first longitudinal bar 11, a first transverse bar 12 that bends at the upper end of the first longitudinal bar 11 and extends laterally, a first upper hook 13 (90-degree hook) that bends at the end of the first transverse bar 12 and extends downward, and a first lower hook 15 (180-degree hook) that bends at the lower end of the first longitudinal bar 11 and extends upward, forming a roughly L-shape. Here, the first upper hook 13 in the illustrated example is a 90-degree hook, but it may also be a 135-degree hook or a 180-degree hook.

[0049] On the other hand, the second reinforcing bar 10A has a roughly U-shape, which is formed by a second transverse bar 14A extending laterally, a pair of second longitudinal bars 11A that bend at both ends of the second transverse bar 14A and extend upward, and second upper hooks 13A (180-degree hooks) that bend at the ends of each second longitudinal bar 11A and extend upward in a continuous manner. Here, the second upper hooks 13A in the illustrated example are 180-degree hooks, but they may also be 90-degree hooks or 135-degree hooks.

[0050] The first precast concrete slab 20 has vertical slabs 22 that extend in the longitudinal direction, and the first vertical reinforcement bars 11 that extend in the longitudinal direction are embedded in the vertical slabs 22, thereby attaching the first reinforcing bars 10 to the first precast concrete slab 20.

[0051] More specifically, the lower part of the vertical reinforcement 11 protrudes from the lower surface 24 of the vertical plate 22, and the first vertical reinforcement 11 is embedded in the vertical plate 22.

[0052] On the other hand, the second precast concrete slab 40 has a horizontal slab 42 that extends laterally, and the second horizontal reinforcement bar 14A that extends laterally is embedded in the horizontal slab 42, thereby attaching the second reinforcing bar 10A to the second precast concrete slab 40.

[0053] More specifically, the upper part of the pair of second vertical reinforcements 11A protrudes from the upper surface 44 of the second precast concrete slab 40, and a portion of the second horizontal reinforcement 14A and the second vertical reinforcement 11A are embedded in the horizontal slab 42.

[0054] Here, although not shown in the diagram, the thickness of the first precast concrete slab 20 may be increased, and the upper main reinforcement (for example, one) may be embedded inside the first precast concrete slab 20. In the form where the thickness of the first precast concrete slab is increased, a portion of the upper main reinforcement 30 is further embedded in addition to the first vertical reinforcement 11, which is preferable because it can suppress cracking of the first precast concrete slab 20 that constitutes the first reinforced precast concrete slab 60 before the half-precast beam is manufactured.

[0055] Multiple upper main reinforcement bars 30 extending in the longitudinal direction are attached below multiple first horizontal reinforcement bars 12, and multiple lower main reinforcement bars 50 extending in the longitudinal direction are attached above multiple second horizontal reinforcement bars 14A. By attaching multiple upper main reinforcement bars 30 to a first precast concrete slab 20 to which multiple first reinforcing bars 10 are attached, a first reinforced precast concrete slab 60 is formed. In addition, by attaching multiple lower main reinforcement bars 50 to a second precast concrete slab 40 to which multiple second reinforcing bars 10A are attached, a second reinforced precast concrete slab 60A is formed.

[0056] Here, the entirety of the first reinforced precast concrete slab 60 and the second reinforced precast concrete slab 60A shown in the diagram may be manufactured in a factory or the like, transported to the site and installed in the designated location, or the first precast concrete slab 20 and the upper main reinforcement 30 may be transported to the site without the upper main reinforcement 30 attached (all parts except the upper main reinforcement 30 may be manufactured in a factory or the like), and after the first precast concrete slab 20 is installed in the designated location at the site, the upper main reinforcement 30 may be attached to form the first reinforced precast concrete slab 60.

[0057] The following explanation assumes that the half-precast beam to be manufactured is a beam on the upper floor. Regarding the manufacturing method of the illustrated example, first, as shown in Figure 2(a), a second reinforced precast concrete slab 60A is installed at the beam installation location, and the first reinforced precast concrete slab 60 (in the illustrated example, the first reinforced precast concrete slab 60 on the right) is positioned on top of the second reinforced precast concrete slab 60A.

[0058] In this case, the precast concrete slab 60A with the second reinforcing bar that is installed first has seven lower main reinforcing bars 50 attached to the multiple second horizontal reinforcing bars 14A at equal or approximately equal intervals in the horizontal direction.

[0059] Furthermore, the first reinforced precast concrete slab 60 (the first reinforced precast concrete slab 60 on the right in the illustrated example), which is installed prior to the second reinforced precast concrete slab 60A, has four upper main reinforcement bars 30 attached to multiple first horizontal bars 12 at equal or approximately equal intervals in the horizontal direction.

[0060] On the other hand, the first reinforced precast concrete slab 60 (the first reinforced precast concrete slab 60 on the left in the illustrated example), which is installed later than the second reinforced precast concrete slab 60A, has three upper main reinforcements 30 attached to multiple first horizontal reinforcements 12 at equal or approximately equal intervals in the horizontal direction.

[0061] Next, as shown in Figure 2(b), the right-side first reinforced precast concrete slab 60 is positioned such that the first lower hooks 15 and the second upper hooks 13A of both the first reinforced precast concrete slab 60 and the second reinforced precast concrete slab 60A intersect.

[0062] In this positioning posture, a gap R is created between the lower surface 24 of the vertical plate 22 and the upper surface 44 of the horizontal plate 42.

[0063] Next, the left-side precast concrete slab 60 with the first reinforcement bar, which is to be installed laterally, is moved laterally in the X1 direction, and the lateral movement is stopped when the first upper hook 13 has passed the upper main reinforcement bar 30 at the left end.

[0064] Next, as shown in Figure 2(c), the left-side first reinforced precast concrete slab 60 is lowered downward in the X2 direction, so that the upper main reinforcement 30 at the right end of the right-side first reinforced precast concrete slab 60 is sandwiched between the first upper hooks 13 on both sides, and the left-side first reinforced precast concrete slab 60 and the second reinforced precast concrete slab 60A are positioned so that the first lower hooks 15 and second upper hooks 13A on both sides intersect.

[0065] Thus, in a pair of precast concrete slabs 60 with first reinforcement bars, a single upper main reinforcement bar 30 is enclosed inside where the first upper hooks 13 of both slabs intersect, thereby integrating the first reinforcing bars 10 of both slabs. Similarly, in the precast concrete slab 60 with first reinforcement bars and the precast concrete slab 60A with second reinforcement bars, the first reinforcing bar 10 and the second reinforcing bar 10A are integrated by intersecting the first lower hooks 15 and the second upper hooks 13A of both slabs. At this time, it is desirable to use the spacing R to reach in from the outside and tie together the overlapping portions of the first vertical reinforcement bar 11 and the first lower hook 15 and the second vertical reinforcement bar 11A and the second upper hook 13A to integrate the first reinforcing bar 10 and the second reinforcing bar 10A, which are in an upper-lower relationship.

[0066] As shown in Figure 2(c), the two first upper hooks 13 sandwich one upper main reinforcement bar 30, and the first lower hook 15 and the second upper hook 13A intersect, so that multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals in the lateral direction relative to the first horizontal reinforcement bar 12. On the other hand, multiple lower main reinforcement bars 50 (seven in the illustrated example) are already arranged at equal or approximately equal intervals in the lateral direction relative to the second horizontal reinforcement bar 14A. In this way, the reinforcement is arranged automatically, and a gap G is formed in the area surrounded by the pair of first reinforced precast concrete slabs 60 and second reinforced precast concrete slabs 60A.

[0067] In the state shown in Figure 2(c), there is a gap R between the lower surface 24 of the vertical panel 22 and the upper surface 44 of the horizontal panel 42, so a formwork K is installed to close this gap R.

[0068] In this way, when a second reinforced precast concrete slab 60A and a pair of first reinforced precast concrete slabs 60 are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor required for beam reinforcement placement.

[0069] Next, as shown in Figure 2(d), concrete is poured into the gap G to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100 having a pair of first reinforced precast concrete slabs 60 and second reinforced precast concrete slabs 60A and a post-cast concrete body 70.

[0070] In the manufacturing method shown in the illustration, the first precast concrete slab 20 and the second precast concrete slab 40 function as formwork (side frames) when forming the later-cast concrete body 70, while remaining as components of the half-precast beam 100. This minimizes the installation and removal of the side frames, thereby reducing the labor involved in formwork installation and removal.

[0071] Thus, the method for manufacturing a half-precast beam using a first reinforced precast concrete slab 60 and a second reinforced precast concrete slab 60A allows for labor savings in formwork installation and removal, while eliminating or reducing the labor required for beam reinforcement work. This method offers superior manufacturability (or constructability) of the beam and improves overall quality.

[0072] Next, with reference to Figure 3, a method for manufacturing another example of the half-precast beam according to the embodiment will be described. Here, Figures 3(a) to (c) are process diagrams for manufacturing another example of the half-precast beam according to the embodiment, and both show a longitudinal cross-sectional view perpendicular to the longitudinal direction of the other example of the half-precast beam according to the embodiment.

[0073] The precast concrete slab 60B with third reinforcement, which is applied to the manufacturing method shown in Figure 3, differs from the precast concrete slab 60 with first reinforcement in that each of the separate third vertical reinforcements 11C, which extends in the longitudinal direction and is connected to a separate third vertical reinforcement 11C, and to the separate third vertical reinforcement 11C, which is connected to a separate third vertical reinforcement 19 (truss reinforcement) that extends in the longitudinal direction and has a wavy shape, is embedded at intervals along the longitudinal direction of the precast concrete slab 20A, and each of the separate third vertical reinforcements 11B of the multiple third reinforcement reinforcements 10B, which are roughly L-shaped, is connected to each of the wavy reinforcement 19 by binding or welding. Here, although not shown in the diagram, the separate third reinforcing bar may comprise two separate third longitudinal bars and a corrugated reinforcing bar arranged between them and connected to them, with one of the separate third longitudinal bars embedded in the third precast concrete slab and the third longitudinal bar of the third reinforcing bar connected to the other separate third longitudinal bar.

[0074] The third reinforcing bar 10B consists of a third longitudinal bar 11B, a third transverse bar 12B that bends at the upper end of the third longitudinal bar 11B and extends laterally, a third upper hook 13B (90-degree hook) that bends at the end of the third transverse bar 12B and extends downward, and a third lower hook 15B (180-degree hook) that bends at the lower end of the third longitudinal bar 11B, which extends upward, forming a roughly L-shape. Here, the third upper hook 13B in the illustrated example is a 90-degree hook, but it may also be a 135-degree hook or a 180-degree hook.

[0075] By embedding one of the separate third vertical bars 11C of each of the multiple separate third reinforcing bars 10C into the vertical slab 22A, multiple separate third reinforcing bars 10C are attached to the third precast concrete slab 20A, and a corresponding third reinforcing bar 10B is attached to each separate third reinforcing bar 10C.

[0076] Since a separate third vertical reinforcement bar 11C is embedded in the vertical slab 22A, the lower end of the third vertical reinforcement bar 11B and the third lower hook 15B of the third reinforcing bar 10B connected to the corrugated reinforcement bar 19 do not protrude downward from the lower surface 24 of the vertical slab 22A.

[0077] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 3(a), a second reinforced precast concrete slab 60A is installed at the beam installation location, and a third reinforced precast concrete slab 60B (in the illustrated example, the third reinforced precast concrete slab 60B on the right) is positioned on top of the second reinforced precast concrete slab 60A.

[0078] In this case, the precast concrete slab 60A with the second reinforcing bar that is installed first has seven lower main reinforcing bars 50 attached to the multiple second horizontal reinforcing bars 14A at equal or approximately equal intervals in the horizontal direction.

[0079] Furthermore, the third reinforced precast concrete slab 60B (the example shown is the third reinforced precast concrete slab 60B on the right), which is installed prior to the second reinforced precast concrete slab 60A, has four upper main reinforcement bars 30 attached to multiple first horizontal bars 12 at equal or approximately equal intervals in the horizontal direction.

[0080] On the other hand, the third reinforced precast concrete slab 60B (the example shown is the third reinforced precast concrete slab 60B on the left), which is installed later than the second reinforced precast concrete slab 60A, has three upper main reinforcement bars 30 attached to multiple first horizontal bars 12 at equal or approximately equal intervals in the horizontal direction.

[0081] Next, as shown in Figure 3(b), the right-side precast concrete slab 60B with third reinforcement and the right-side precast concrete slab 60A with second reinforcement are positioned such that the first lower hooks 15 and second upper hooks 13A of both slabs intersect.

[0082] In this positioning posture, the lower surface 24 of the vertical plate 22A abuts against the upper surface 44 of the horizontal plate 42, and no separation R occurs as shown in Figure 2(b).

[0083] Next, the precast concrete slab 60B with the third reinforcement bar on the left side, which will be installed laterally, is moved laterally in the X3 direction, and the lateral movement is stopped when the third upper hook 13B passes the upper main reinforcement bar 30 at the left end.

[0084] Next, as shown in Figure 3(c), the left precast concrete slab 60B with the third reinforcement bar is lowered downwards, and the upper main reinforcement bar 30 at the right end of the right precast concrete slab 60B with the third reinforcement bar is positioned so that both third upper hooks 13B sandwich it, and the left precast concrete slab 60B with the third reinforcement bar and the second precast concrete slab 60A are positioned so that their respective third lower hooks 15B and second upper hooks 13A intersect.

[0085] Thus, in a pair of precast concrete slabs 60B with third reinforcement bars, a single upper main reinforcement bar 30 is enclosed inside where the third upper hooks 13B of both slabs intersect, thereby integrating the third reinforcing bars 10B of both slabs. In the precast concrete slabs 60B with third reinforcement bars and precast concrete slabs 60A with second reinforcement bars, the third reinforcing bars 10B and second reinforcing bars 10A are integrated by intersecting the third lower hooks 15B and second upper hooks 13A of both slabs.

[0086] As shown in Figure 3(c), the two third upper hooks 13B sandwich one upper main reinforcement bar 30, and the third lower hook 15B and the second upper hook 13A intersect, so that multiple upper main reinforcement bars 30 (seven in the illustrated example) are arranged at equal or approximately equal intervals in the lateral direction relative to the third transverse reinforcement bar 12B. On the other hand, multiple lower main reinforcement bars 50 (seven in the illustrated example) are already arranged at equal or approximately equal intervals in the lateral direction relative to the second transverse reinforcement bar 14A. In this way, the reinforcement is arranged automatically, and a gap G is formed in the area enclosed by the pair of precast concrete slabs 60B with third reinforcement bars and precast concrete slabs 60A with second reinforcement bars.

[0087] In this way, when a second reinforced precast concrete slab 60A and a pair of third reinforced precast concrete slabs 60B are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor required for beam reinforcement placement.

[0088] Next, as shown in Figure 3(c), concrete is poured into the gap G to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100A having a pair of third reinforced precast concrete slabs 60B and second reinforced precast concrete slabs 60A, and a post-cast concrete body 70.

[0089] 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.

[0090] Furthermore, since the entire third reinforcing bar 10B, which is roughly L-shaped and tied to a separate third reinforcing bar 10C that has a separate third longitudinal reinforcement bar 11C embedded in the third precast concrete slab 20A, is embedded in the later-cast concrete body 70, the shear reinforcement effect of the third reinforcing bar 10B can be enhanced. As a result, even if the degree of integration between the third precast concrete slab 20A and the later-cast concrete body 70 is not good, a high shear reinforcement effect can be achieved by the roughly L-shaped third reinforcing bar 10B.

[0091] Furthermore, the corrugated reinforcing bars 19, which extend vertically and exhibit a wavy shape, are connected to the third longitudinal bar 11B of the roughly L-shaped third reinforcing bar 10B and to the separate third longitudinal bar 11C of the separate third reinforcing bar 10C, thereby enabling a stronger integration of the two. In addition, with this configuration, the third longitudinal bar 11B, the separate third longitudinal bar 11C, and the corrugated reinforcing bars 19 between them can resist, in a mechanism similar to that of a truss beam, the pressure acting on the inside of the third precast concrete slab 20A when concrete is poured during the construction of the post-cast concrete body 70, and the earth pressure acting on the outside of the third precast concrete slab 20A when soil is backfilled before concrete is poured.

[0092] Next, with reference to Figure 4, a manufacturing method for yet another example of the half-precast beam according to the embodiment will be described. Here, Figures 4(a) to (e) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the embodiment, and both show a longitudinal cross-sectional view perpendicular to the longitudinal direction of yet another example of the half-precast beam according to the embodiment.

[0093] The half-precast beam 100B, which is applied to the manufacturing method shown in Figure 4, differs from the half-precast beam 100 in that it is made of SRC (steel-reinforced concrete) with a steel beam 80 embedded inside the later-cast concrete body 70.

[0094] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 4(a), a second reinforced precast concrete slab 60A is installed at the beam installation location, a steel beam 80 is placed on top of the second reinforced precast concrete slab 60A, and then the first reinforced precast concrete slab 60 (in the illustrated example, the first reinforced precast concrete slab 60 on the right) is positioned on top of that.

[0095] Next, as shown in Figure 4(b), the right-side first reinforced precast concrete slab 60 is lowered downward in the X4 direction, and the right-side first reinforced precast concrete slab 60 is positioned such that the first lower hooks 15 and the second upper hooks 13A of both the first reinforced precast concrete slab 60 and the second reinforced precast concrete slab 60A intersect.

[0096] In this positioning posture, a gap R is created between the lower surface 24 of the vertical plate 22 and the upper surface 44 of the horizontal plate 42.

[0097] Next, as shown in Figure 4(c), the left-side first reinforced precast concrete slab 60, which is to be installed laterally, is moved laterally in the X5 direction until the first upper hook 13 passes the upper main reinforcement 30 at the left end, at which point the lateral movement is stopped.

[0098] Next, as shown in Figure 4(d), the left-side first reinforced precast concrete slab 60 is lowered downward in the X6 direction, so that the upper main reinforcement 30 at the right end of the right-side first reinforced precast concrete slab 60 is sandwiched between the first upper hooks 13 on both sides, and the left-side first reinforced precast concrete slab 60 and the second reinforced precast concrete slab 60A are positioned so that the first lower hooks 15 and second upper hooks 13A on both sides intersect.

[0099] As shown in Figure 4(d), the two first upper hooks 13 sandwich one upper main reinforcement bar 30, and the first lower hook 15 and the second upper hook 13A intersect, thereby arranging multiple upper main reinforcement bars 30 (seven in the illustrated example) at equal or approximately equal intervals in the lateral direction relative to the first transverse reinforcement bar 12. On the other hand, multiple lower main reinforcement bars 50 (seven in the illustrated example) are already arranged at equal or approximately equal intervals in the lateral direction relative to the second transverse reinforcement bar 14A. In this way, the reinforcement is arranged automatically, and a gap G is formed in which a steel beam 80 is installed in the area enclosed by the pair of first reinforced precast concrete slabs 60 and second reinforced precast concrete slabs 60A.

[0100] In the state shown in Figure 4(d), there is a gap R between the lower surface 24 of the vertical panel 22 and the upper surface 44 of the horizontal panel 42, so a formwork K is installed to close this gap R.

[0101] In this way, when a second reinforced precast concrete slab 60A and a pair of first reinforced precast concrete slabs 60 are installed with a gap G between them, the beam reinforcement is placed simultaneously, thus eliminating or reducing the labor required for beam reinforcement placement.

[0102] Next, as shown in Figure 4(e), concrete is poured into the gap G to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100B having a pair of first reinforced precast concrete slabs 60 and second reinforced precast concrete slabs 60A, and a post-cast concrete body 70 in which a steel beam 80 is embedded.

[0103] In the manufacturing method shown in the illustration, the first precast concrete slab 20 and the second precast concrete slab 40 function as formwork (side frames) when forming the later-cast concrete body 70, while remaining as components of the half-precast beam 100. This minimizes the installation and removal of the side frames, thereby reducing the labor involved in formwork installation and removal.

[0104] Thus, the method for manufacturing a half-precast beam using a first reinforced precast concrete slab 60 and a second reinforced precast concrete slab 60A allows for labor savings in formwork installation and removal, while eliminating or reducing the labor required for beam reinforcement work. This method offers superior manufacturability (or constructability) of the beam and improves overall quality.

[0105] Furthermore, because it is made of SRC with a steel beam 80 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.

[0106] Next, with reference to Figure 5, a manufacturing method for yet another example of the half-precast beam according to the embodiment will be described. Here, Figures 5(a) to (d) are process diagrams for the manufacturing method of yet another example of the half-precast beam according to the 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 embodiment.

[0107] The half-precast beam 100C, which is applied to the manufacturing method shown in Figure 5, differs from the half-precast beam 100, which has a second reinforced precast concrete slab 60A, in that it has a reinforced concrete slab 60C for on-site cast pressure-resistant slabs, which is manufactured by concrete pouring on-site.

[0108] Regarding the manufacturing method of the illustrated example, first, as shown in Figure 5(a), multiple second reinforcing bars 10A are placed at the beam installation position, multiple lower main bars 50 are placed above multiple second transverse bars 14A, and two layers of mutually intersecting base bars 16 are placed. Concrete is then poured so as to embed the multiple second transverse bars 14A, the lower main bars 50, and the base bars 16 to manufacture a cast-in-place pressure-resistant concrete slab 40A, and a cast-in-place pressure-resistant concrete slab 60C with reinforcement is manufactured.

[0109] The second reinforcing bar 10A, the second vertical reinforcement bar 11A, and the second upper hook 13A are provided protruding from the upper surface 45 of the concrete slab 40A for cast-in-place pressure slabs.

[0110] Next, the first reinforced precast concrete slab 60 (the example shown is the first reinforced precast concrete slab 60 on the right) is positioned on top of the reinforced concrete slab 60C for cast-in-place pressure-resistant slabs.

[0111] Next, as shown in Figure 5(b), the right-side first reinforced precast concrete slab 60 and the reinforced cast-in-place pressure-resistant concrete slab 60C are positioned such that the first lower hooks 15 and the second upper hooks 13A of both slabs intersect.

[0112] In this positioning posture, a gap R is created between the lower surface 24 of the vertical plate 22 and the upper surface 45 of the concrete plate 40A for cast-in-place pressure-resistant slabs.

[0113] Next, the left-side precast concrete slab 60 with the first reinforcement bar, which is to be installed laterally, is moved laterally in the X7 direction, and the lateral movement is stopped when the first upper hook 13 passes the upper main reinforcement bar 30 at the left end.

[0114] Next, as shown in Figure 5(c), the left-side first reinforced precast concrete slab 60 is lowered downward in the X8 direction, so that the upper main reinforcement 30 at the right end of the right-side first reinforced precast concrete slab 60 is sandwiched between the first upper hooks 13 on both sides, and the left-side first reinforced precast concrete slab 60 and the reinforced cast-in-place pressure-resistant concrete slab 60C are positioned so that the first lower hooks 15 and second upper hooks 13A on both sides intersect.

[0115] As shown in Figure 5(c), the two first upper hooks 13 sandwich one upper main reinforcement bar 30, and the first lower hook 15 and the second upper hook 13A intersect, thereby arranging multiple upper main reinforcement bars 30 (seven in the illustrated example) at equal or approximately equal intervals in the lateral direction relative to the first horizontal reinforcement bar 12. Meanwhile, multiple lower main reinforcement bars 50 (seven in the illustrated example) are already arranged at equal or approximately equal intervals in the lateral direction relative to the second horizontal reinforcement bar 14A. In this way, the reinforcement is arranged automatically, and a gap G is formed in the area surrounded by the pair of first reinforced precast concrete slabs 60 and reinforced cast-in-place pressure-resistant concrete slabs 60C.

[0116] In the state shown in Figure 5(c), there is a gap R between the lower surface 24 of the vertical plate 22 and the upper surface 45 of the cast-in-place pressure-resistant concrete plate 40A, so formwork K is installed to close this gap R.

[0117] In this way, when a concrete slab 60C with reinforced steel and a pair of precast concrete slabs 60 with first reinforced steel are installed while forming a gap G between them, the beam reinforcement is placed at the same time, thus eliminating or reducing the labor required for beam reinforcement placement.

[0118] Next, as shown in Figure 5(d), concrete is poured into the gap G to form a post-cast concrete body 70, thereby manufacturing a half-precast beam 100 having a pair of first reinforced precast concrete slabs 60 and reinforced cast-in-place pressure-resistant concrete slabs 60C, and a post-cast concrete body 70.

[0119] In the manufacturing method shown in the illustration, the pair of first precast concrete slabs 20 function as formwork (side frames) when forming the later-cast concrete body 70, while remaining as components of the half-precast beam 100. This minimizes the installation and removal of the side frames, thereby reducing the labor involved in formwork installation and removal.

[0120] Thus, the method for manufacturing a half-precast beam using the first reinforced precast concrete slab 60 and the reinforced cast-in-place pressure-resistant concrete slab 60C allows for labor savings in formwork installation and removal, while eliminating or reducing the labor required for beam reinforcement placement. This method offers superior beam manufacturability (or constructability) and improved quality.

[0121] Although not shown in the illustration, in the manufacturing method shown in Figure 5, the third reinforced precast concrete slab 60B shown in Figure 3 may be applied, and a half-precast beam may be manufactured using a pair of third reinforced precast concrete slabs 60B and a reinforced cast-in-place pressure-resistant concrete slab 60C. Alternatively, in the manufacturing method shown in Figure 5, a half-precast beam may be manufactured by the manufacturing method that includes the steel beam 80 shown in Figure 4.

[0122] 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. [Explanation of symbols]

[0123] 10: First reinforcing muscle 10A: Second reinforcing muscle 10B: Third reinforcing muscle 10C: Separate third reinforcement bar 11: First vertical line 11A: Second vertical reinforcement 11B: Third vertical line 11C: Separate third vertical reinforcement 12: First horizontal line 12B: Third horizontal line 13: First upper hook (90-degree hook) 13A: Second upper hook (180-degree hook) 13B: Third upper hook (90-degree hook) 14A: Second horizontal reinforcement 14B: Third lower transverse muscle 15: First lower hook (180-degree hook) 16: Bottom plate muscle 19: Wavy reinforcing muscles 20: First precast concrete slab 20A: Third precast concrete panel 22,22A: Vertical version 30: Top main reinforcement 40: Second precast concrete slab 40A: Concrete slab for cast-in-place pressure-resistant slabs 42:Horizontal version 50: Bottom main reinforcement 60: First reinforcing steel precast concrete panel 60A: Precast concrete slab with second reinforcing bars 60B: Third reinforced precast concrete panel 60C: Reinforced concrete slab for cast-in-place pressure-resistant construction. 70: Post-cast concrete body 80: Steel beam 100, 100A, 100B, 100C: Half-precast beams G: Gap R: Separation K: Formwork

Claims

1. A pair of precast concrete slabs with first reinforcing bars, each of which has a first vertical bar, a first horizontal bar that bends at the upper end of the first vertical bar and extends laterally, a first upper hook that bends at the end of the first horizontal bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first vertical bar and extends upward, forming a roughly L-shape, the first vertical bars of each of the first reinforcing bars are embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars that extend in the longitudinal direction are attached below the plurality of first horizontal bars, The second reinforced concrete slab comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second reinforcing bars, each having a substantially U-shape formed by a series of second upper hooks that bend at the ends of each of the second longitudinal bars, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks that bend upward, each of which is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main reinforcement extending along the longitudinal direction is attached above the plurality of second transverse bars and embedded in the second precast concrete slab, A half-precast beam characterized in that the pair of first precast concrete slabs are arranged with a gap between them, with the first horizontal reinforcement and the first upper hook intersecting, and the pair of first precast concrete slabs are arranged above the second reinforced precast concrete slab, with the first lower hook and the second upper hook intersecting, and a post-cast concrete body is provided in the gap.

2. The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, The second reinforced concrete slab comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second reinforcing bars, each having a substantially U-shape formed by a series of second upper hooks that bend at the ends of each of the second longitudinal bars, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks that bend upward, each of which is embedded at intervals along the longitudinal direction of the second precast concrete slab, and a lower main reinforcement extending along the longitudinal direction is attached above the plurality of second transverse bars and embedded in the second precast concrete slab, A half-precast beam characterized in that the pair of third precast concrete slabs are arranged with a gap between them, with the third horizontal reinforcement and the third upper hook intersecting, and the pair of third precast concrete slabs are arranged above the second reinforced precast concrete slab, with the third lower hook and the second upper hook intersecting, and a post-cast concrete body is provided in the gap.

3. A pair of precast concrete slabs with first reinforcing bars, each of which has a first vertical bar, a first horizontal bar that bends at the upper end of the first vertical bar and extends laterally, a first upper hook that bends at the end of the first horizontal bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first vertical bar and extends upward, forming a roughly L-shape, the first vertical bars of each of the first reinforcing bars are embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars that extend in the longitudinal direction are attached below the plurality of first horizontal bars, The concrete slab for cast-in-place pressure-resistant slabs with reinforcement bars comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second upper hooks, each of which is a 90-degree hook, a 135-degree hook, or a 180-degree hook, bending at the ends of each of the second longitudinal bars and opening upward in a roughly U-shape, with each of the second transverse bars of the plurality of second reinforcing bars embedded at intervals in the concrete slab for cast-in-place pressure-resistant slabs, and a plurality of lower main reinforcement bars arranged above the plurality of second transverse bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, A half-precast beam characterized in that the pair of first precast concrete slabs are arranged with a gap between them, with the corresponding first upper hooks of the pair of first precast concrete slabs intersecting, and the pair of first precast concrete slabs are arranged above the reinforced concrete slab with a reinforced concrete slab, with the first lower hooks of the pair of first precast concrete slabs and the corresponding second upper hooks of the reinforced concrete slab for cast-in-place pressure-resistant slabs intersecting, and a post-cast concrete body provided in the gap.

4. The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, The concrete slab for cast-in-place pressure-resistant slabs with reinforcement bars comprises a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and a plurality of second upper hooks, each of which is a 90-degree hook, a 135-degree hook, or a 180-degree hook, bending at the ends of each of the second longitudinal bars and opening upward in a roughly U-shape, with each of the second transverse bars of the plurality of second reinforcing bars embedded at intervals in the concrete slab for cast-in-place pressure-resistant slabs, and a plurality of lower main reinforcement bars arranged above the plurality of second transverse bars and embedded in the concrete slab for cast-in-place pressure-resistant slabs, A half-precast beam characterized in that the pair of third precast concrete slabs are arranged with a gap between them, with the corresponding third upper hooks of each of the pair of third precast concrete slabs intersecting, and the pair of third precast concrete slabs are arranged above the reinforced concrete slab with a reinforced concrete slab, with the third lower hooks of the pair of third precast concrete slabs intersecting the second upper hooks of the reinforced concrete slab with a reinforced concrete slab, and a post-cast concrete body provided in the gap.

5. A half-precast beam according to any one of claims 1 to 4, characterized in that a steel beam is embedded in the aforementioned post-cast concrete body.

6. A pair of precast concrete slabs with first reinforcing bars, each of which has a first vertical bar, a first horizontal bar that bends at the upper end of the first vertical bar and extends laterally, a first upper hook that bends at the end of the first horizontal bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first vertical bar and extends upward, forming a roughly L-shape, the first vertical bars of each of the first reinforcing bars are embedded at intervals in the longitudinal direction of the first precast concrete slab, and upper main bars that extend in the longitudinal direction are attached below the plurality of first horizontal bars, A precast concrete slab with second reinforcing bars is prepared, in which each of the second reinforcing bars of the second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second reinforcing bars and embedded in the second precast concrete slab, and the second transverse bars of the second reinforcing bars are embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second transverse bars and embedded in the second precast concrete slab, Position the second reinforced precast concrete slab, Move one of the first reinforced precast concrete slabs so that the first lower hooks of each of the multiple first reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars. The other precast concrete slab with first reinforcement is moved so that the corresponding first upper hooks of both precast concrete slabs with first reinforcement intersect, and a gap is created between the two precast concrete slabs with first reinforcement to position it. A formwork is installed to close the gap between the upper surface of the second reinforced precast concrete slab and the lower surface of the first reinforced precast concrete slab. 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.

7. The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars, A precast concrete slab with second reinforcing bars is prepared, in which each of the second reinforcing bars of the second reinforcing bars is embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second reinforcing bars and embedded in the second precast concrete slab, and the second transverse bars of the second reinforcing bars are embedded at intervals along the longitudinal direction of the second precast concrete slab, and lower main reinforcing bars extending along the longitudinal direction are attached above the multiple second transverse bars and embedded in the second precast concrete slab, Position the second reinforced precast concrete slab, Move one of the precast concrete slabs with the third reinforcing bars so that the third lower hooks of each of the multiple third reinforcing bars intersect with the second upper hooks of the corresponding second reinforcing bars. The other precast concrete slab with the third reinforcement is moved so that the corresponding third upper hooks of both precast concrete slabs with the third reinforcement intersect, and a gap is created between the two precast concrete slabs with the third reinforcement to position it. 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.

8. Prepare a pair of precast concrete slabs with first reinforcing bars, each of which consists of a first vertical bar, a first horizontal bar that bends at the upper end of the first vertical bar and extends laterally, a first upper hook that bends at the end of the first horizontal bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a first lower hook that bends at the lower end of the first vertical bar and extends upward, forming a roughly L-shape. Each of the first vertical bars of the 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 horizontal bars. Multiple second reinforcing bars are arranged, each consisting of a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and second upper hooks, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks, bending at the ends of each of the second longitudinal bars, forming a roughly U-shape that opens upward in a continuous manner, and multiple lower main bars are arranged above the multiple second transverse bars. A concrete slab for a cast-in-place pressure-resistant slab is fabricated by pouring concrete so as to embed multiple second horizontal reinforcements and the lower main reinforcements. While crossing the first lower hooks of the pair of first precast concrete slabs and the corresponding second upper hooks of the cast-in-place pressure-resistant concrete slab, the pair of first precast concrete slabs are positioned above the cast-in-place pressure-resistant concrete slab with a gap between them. A formwork is installed to close the gap between the upper surface of the cast-in-place pressure-resistant concrete slab and the lower surface of the first reinforced precast concrete slab. 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.

9. The device comprises multiple third reinforcing bars, each consisting of a third longitudinal bar, a third transverse bar that bends at the upper end of the third longitudinal bar and extends laterally, a third upper hook that bends at the end of the third transverse bar and is a 90-degree hook, a 135-degree hook, or a 180-degree hook, and a third lower hook that bends at the lower end of the third longitudinal bar and extends upward, forming a substantially L-shape. The structure comprises a plurality of separate third reinforcing bars, each comprising a separate third longitudinal bar and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, connected to the separate third longitudinal bar, or a plurality of separate third reinforcing bars, each comprising a pair of separate third longitudinal bars and a wavy reinforcing bar extending longitudinally and exhibiting a wavy shape, sandwiched between and connected to the pair of separate third longitudinal bars. At least one of the separate third reinforcing bars, each of which has a separate third longitudinal bar, is embedded at intervals in the longitudinal direction of the third precast concrete slab. The third longitudinal bar of the corresponding third reinforcing bar is tied or welded to the wavy reinforcing bar or the third longitudinal bar of each of the aforementioned separate third reinforcing bars. A pair of precast concrete slabs with third reinforcing bars are prepared, each having upper main reinforcing bars extending in the longitudinal direction attached below a plurality of the aforementioned third transverse bars. Multiple second reinforcing bars are arranged, each consisting of a second transverse bar extending laterally, a pair of second longitudinal bars bending at both ends of the second transverse bar and extending upward, and second upper hooks, which are 90-degree hooks, 135-degree hooks, or 180-degree hooks, bending at the ends of each of the second longitudinal bars, forming a roughly U-shape that opens upward in a continuous manner, and multiple lower main bars are arranged above the multiple second transverse bars. A concrete slab for a cast-in-place pressure-resistant slab is fabricated by pouring concrete so as to embed multiple second horizontal reinforcements and the lower main reinforcements. While crossing the third lower hooks of the pair of third precast concrete slabs with the corresponding second upper hooks of the cast-in-place pressure-resistant concrete slab, the pair of third precast concrete slabs are positioned above the cast-in-place pressure-resistant concrete slab with a gap between them. 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.

10. Further steel beams were prepared, A method for manufacturing a half-precast beam according to any one of claims 6 to 9, characterized in that concrete is poured after positioning the steel beam in the gap to form the post-cast concrete body.

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