Anchorage structure of main reinforcement in foundation beams

Abstract

To provide a foundation beam main reinforcement anchorage structure that allows the use of high-strength reinforcing bars or partially high-strength reinforcing bars as main reinforcement for foundation beams made of ordinary-strength concrete, while fully utilizing the performance of the main reinforcement bars and ensuring sufficient anchorage strength, thereby reducing the amount of main reinforcement bars to be placed in the foundation beam. [Solution] An anchoring structure for main reinforcement bars 2 used in a foundation beam 1 of a concrete structure, wherein the foundation beam 1 includes an underground beam 13, a foundation column 12 and a footing 11, and an anchoring steel plate 3 is provided at the end of the main reinforcement bars 2, and the main reinforcement bars 2 are either high-strength reinforcement bars or partially high-strength reinforcement bars, and the structure includes at least one of the following structures A and B: (Structure A) a structure in which the anchoring steel plate 3 is in contact with at least one of the surfaces of the foundation column 1 and the footing 11, and (Structure B) a structure in which the anchoring steel plate 3 is embedded inside at least one of the foundation column 1 and the footing 11.

Description

Technical Field

[0001] The present invention relates to a fixing structure for main reinforcement bars of a foundation beam.

Background Art

[0002] Conventionally, proposals have been made to improve the fixing strength of reinforcing bars arranged in concrete structures. Specifically, for example, a fixing structure has been proposed that uses a nut-shaped fixing body provided with a female screw portion that is screwed and fixed to a screw portion formed at the end of a reinforcing bar (main reinforcement bar) (Patent Document 1). In Patent Document 1, the main reinforcement bar is inserted into the column through the inside of the beam, and the fixing strength is ensured by the nut-shaped fixing body provided at the end of the main reinforcement bar. Generally, when using a main reinforcement bar with a fixing body as in Patent Document 1, it is necessary to perform a design to avoid side peeling failure that occurs when the stress acting on the main reinforcement bar becomes greater than the side peeling fixing strength.

[0003] On the other hand, generally, in the vicinity of the end of the foundation beam (ground beam) of a concrete structure, the main reinforcement bars, stirrups, and anchor bolts intersect and are over-reinforced, resulting in problems such as a decrease in the filling workability of concrete and an accompanying decrease in quality. To solve such problems of the foundation beam, as a construction method for reducing the amount of main reinforcement bars, it is conceivable to use high-strength reinforcing bars or partially high-strength reinforcing bars for the main reinforcement bars. Partially high-strength reinforcing bars are reinforcing bars in which only the portions that require strength are processed to be high-strength compared to ordinary reinforcing bars.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Patent Document 1 does not consider configurations in which high-strength reinforcing bars or partially high-strength reinforcing bars are used as main reinforcement. On the other hand, if the anchorage structure of Patent Document 1 is to be considered for use with ordinary-strength concrete constituting the beam, it is necessary to design the standard strength of the main reinforcement to be below the lateral spalling anchorage strength in order to avoid lateral spalling failure. This presents a problem in that it is difficult to fully utilize the performance of the high-strength reinforcing bars or partially high-strength reinforcing bars.

[0006] This invention has been made in view of the above circumstances, and aims to provide a foundation beam main reinforcement anchorage structure that allows the use of high-strength reinforcing bars or partially high-strength reinforcing bars as main reinforcement in a foundation beam made of ordinary-strength concrete, while avoiding lateral spalling failure, allowing the main reinforcement to perform to its full potential, and reducing the amount of main reinforcement to be placed in the foundation beam while ensuring sufficient anchorage strength. [Means for solving the problem]

[0007] The anchoring structure for the main reinforcement of the foundation beam of the present invention was made to solve the above technical problems and is characterized by the following:

[0008] Firstly, the anchoring structure for the main reinforcement of a foundation beam of the present invention is an anchoring structure for the main reinforcement used in the foundation beam of a concrete structure, The aforementioned foundation beam includes underground beams, foundation columns, and footings. A plate-shaped anchoring steel plate is provided at the end of the main reinforcement bar. The main reinforcement is either high-strength reinforcement or partial high-strength reinforcement. Structures A and B below: (Structure A) A structure in which the anchoring steel plate is in contact with at least one of the surfaces of the foundation column and the footing. (Structure B) A structure in which the anchoring steel plate is embedded inside at least one of the foundation column and the footing. It includes at least one of the following. Secondly, in the anchoring structure for the main reinforcement bars of the foundation beam according to the first invention, it is preferable that one anchoring steel plate is provided for two or more groups of main reinforcement bars. Thirdly, in the anchoring structure for the main reinforcement of the foundation beam of the first invention described above, the concrete strength of the underground beam is 24 to 42 N / mm². 2 It is preferable that it be within the range of [specify range]. Fourth, in the anchoring structure for the first foundation beam main reinforcement described above, it is preferable that the thickness of the anchoring steel plate is in the range of 8 to 45 mm. Fifth, in the anchoring structure for the first foundation beam main reinforcement described above, it is preferable that in structure A, at least one of the anchoring steel plates is covered by an additional concrete layer provided on the surface of the foundation column or the footing. Sixth, in the anchoring structure for the first foundation beam main reinforcement described above, it is preferable that the anchoring steel plate functions as formwork when concrete is poured. [Effects of the Invention]

[0009] According to the anchoring structure for the main reinforcement bars of the foundation beam of the present invention, by arranging the anchoring steel plates at the ends of the main reinforcement bars in predetermined positions, the anchoring length and bearing area of ​​the main reinforcement bars can be increased. For this reason, for example, it is possible to use high-strength reinforcement bars or partially high-strength reinforcement bars as the main reinforcement bars for a foundation beam made of ordinary-strength concrete, and the performance of the main reinforcement bars can be fully demonstrated while avoiding lateral spalling failure. Therefore, when high-strength reinforcement bars or partially high-strength reinforcement bars are used as the main reinforcement bars, the amount of main reinforcement bars to be placed in the concrete foundation beam can be reduced, and even in this case, sufficient anchoring strength can be ensured. Furthermore, reducing the amount of main reinforcement can alleviate overcrowding, thereby improving construction accuracy. In addition, as the amount of main reinforcement decreases, the beam cross-section can be reduced, which reduces the amount of excavation required for construction, resulting in shorter construction periods and lower construction costs. [Brief explanation of the drawing]

[0010] [Figure 1]It is a cross-sectional view showing a first embodiment of a fixing structure for main reinforcement bars of a foundation beam according to the present invention. [Figure 2] It is an enlarged cross-sectional view of a fixing structure for main reinforcement bars of a foundation beam in a footing. (A) shows an embodiment in which a fixing steel plate is sandwiched between nuts on the front and back sides, (B) shows an embodiment in which the fixing steel plate is sandwiched between the footing surface and a nut, and (C) shows an embodiment in which the fixing steel plate is disposed in a recess provided in a part of the footing surface and fixed so that the surface of the footing and the surface of the fixing steel plate are flush. [Figure 3] It is a left side view of the fixing structure for main reinforcement bars of the foundation beam shown in FIG. 1. [Figure 4] It is a schematic view showing an embodiment of a partial high-strength reinforcing bar used in the fixing structure for main reinforcement bars of the foundation beam of the present invention. [Figure 5] It is a cross-sectional view showing a second embodiment of a fixing structure for main reinforcement bars of a foundation beam according to the present invention. [Figure 6] It is a cross-sectional view showing a modified example of the first and second embodiments of the fixing structure for main reinforcement bars of a foundation beam according to the present invention. <00—0082>It is a schematic view showing the pattern of a fixing steel plate.

Mode for Carrying Out the Invention

[0011] <—000088>Hereinafter, an embodiment of a fixing structure for main reinforcement bars of a foundation beam according to the present invention will be described in detail based on the drawings.

[0012] In the fixing structure for main reinforcement bars of the foundation beam of the present invention, the foundation beam includes an underground beam, a foundation column, and a footing. A plate-shaped fixing steel plate is disposed at the end of the main reinforcement bar, and by arranging this fixing steel plate at a predetermined position, the fixing length and bearing area of the main reinforcement bar can be increased.

[0013] The fixing structure for main reinforcement bars of the present invention includes at least one of the following structures (Structure A) and (Structure B). (Structure A) The main reinforcement bars extending inside the ground beam penetrate at least one of the inside of the foundation column and the footing, and the fixing steel plate abuts against the surface of at least one of the foundation column and the footing (First Embodiment). (Structure B) The main reinforcement bars extending inside the ground beam are inserted at least up to the inside of one of the foundation column and the footing, and the fixing steel plate is embedded in at least one of the foundation column and the footing (Second Embodiment). In other words, the fixing structure of the main reinforcement bars of the foundation beam of the present invention may be constituted by either (Structure A) or (Structure B), or both.

[0014] <One Aspect of the First Embodiment (the above Structure (A))> FIG. 1 is a cross-sectional view illustrating a first embodiment of the fixing structure of the main reinforcement bars of the foundation beam of the present invention, FIG. 2 is an enlarged cross-sectional view near the surface (side surface) of the footing in the fixing structure of the main reinforcement bars of the foundation beam, and FIG. 3 is a schematic side view of FIG. 1 as viewed from the left direction.

[0015] As illustrated in FIG. 1, in the fixing structure of the first embodiment, a footing 11 is formed at the lower part of the end of the ground beam 13, and a foundation column 12 stands up from this footing 11. The main reinforcement bars 2 are horizontally arranged inside the ground beam 13 and penetrate the footing 11 and the foundation column 12, and the fixing steel plates 3 arranged at the ends of the main reinforcement bars 2 are exposed and abut against the surfaces (side surfaces) of the footing 11 and the foundation column 12. Further, as illustrated in FIG. 3, two main reinforcement bars 2 are arranged at two locations on the surface (side surface) of each of the foundation column 12 and the footing 11 with an interval therebetween, one above the other. In the foundation column 12 and the footing 11, six main reinforcement bar groups each consisting of two main reinforcement bars 2 are formed, and one fixing steel plate 3 is provided at the end of each main reinforcement bar group. The main reinforcement bars 2 used in the fixing structure of the present invention are high-strength reinforcement bars or partially high-strength reinforcement bars instead of the ordinary mild steel bars used for the main reinforcement bars of the foundation beam 1. In the fixing structure of the present invention, by using high-strength reinforcement bars and partially high-strength reinforcement bars as the main reinforcement bars 2 and arranging the fixing steel plates 3 at the ends of the main reinforcement bars 2 at predetermined positions, it is possible to avoid side peeling failure and fully exert the performance of the main reinforcement bars 2, so that the amount of reinforcement of the main reinforcement bars 2 can be reduced.

[0016] High-strength reinforcing bars have a yield strength of 685-755 N / mm². 2 Partially high-strength reinforcement is a type of reinforcement in which a high-strength region meeting the above yield strength conditions is formed in at least a portion of the longitudinal direction of ordinary reinforcement. Partially high-strength reinforcement 21 has a yield strength of 390 N / mm², as shown in Figure 4. 2 In the middle of the normal strength range, with a strength transition region in between, the yield strength is 700 N / mm². 2 Examples include reinforcing bars that form a high-strength region. The location and extent of the high-strength region in the partially high-strength reinforcing bar 21 can be appropriately set according to the overall length of the reinforcing bar and the design.

[0017] The anchoring steel plate 3, which is placed at the end of the main reinforcement bar 2, is a flat steel plate having a predetermined thickness and strength, and is provided with a through-hole of a diameter through which the main reinforcement bar 2 can be inserted. It is necessary to set the anchoring steel plate 3 so that it does not break before the main reinforcement bar 2. If the anchoring steel plate 3 breaks before the main reinforcement bar 2, it will not be possible to integrate the concrete and the main reinforcement bar 2, which may lead to bearing failure or scraping failure of the concrete. From this viewpoint, the plate thickness of the anchoring steel plate 3 is preferably in the range of 8 to 45 mm. In addition, the size (surface area) and shape of the anchoring steel plate 3 can be appropriately determined according to the number of main reinforcement bars 2 to be installed and the construction conditions of the foundation beam 1.

[0018] In the configuration of the anchoring structure for the main reinforcement of the foundation beam according to the first embodiment, the arrangement of the anchoring steel plate 3 at the end of the main reinforcement 2 is not particularly limited as long as the main reinforcement 2 and the anchoring steel plate 3 are firmly fixed to each other. For example, as shown in Figures 2(A), 2(B), and 2(C), the anchoring steel plate 3 can be fixed to the end of the main reinforcement 2 by one or more nuts 4 screwed onto the main reinforcement 2. Specifically, in the embodiment illustrated in Figure 2(A), the anchoring steel plate 3 is sandwiched between a nut 4 located on the inside side of the footing 11 and two nuts 4 located on the tip side of the main reinforcement 2, and the anchoring steel plate 3 is fixed so as to abut against the surface of the footing 11. In the embodiment illustrated in Figure 2(B), the anchoring steel plate 3 is fixed so as to abut against the surface of the footing 11 by using two nuts 4 stacked on top of each other on the surface side of the footing 11. Furthermore, in the embodiment illustrated in Figure 2(C), the anchoring steel plate 3 is placed in a recess 6 provided on a part of the surface of the footing 11, and the anchoring steel plate 3 is fixed by using two nuts 4 on the surface side of the footing 11 so that the surface of the footing 11 and the surface of the anchoring steel plate 3 are flush. In addition to the above method, the anchoring steel plate 3 may also be fixed using a nut-shaped anchoring body such as an oni plate or screw plate, or the end of the main reinforcement 2 and the anchoring steel plate 3 may be fixed by welding or the like.

[0019] The concrete strength of the underground beam 13 to which the anchoring structure for the main reinforcement of the foundation beam of the present invention is applied can be appropriately set according to the design of the foundation beam 1, but is typically 24 to 42 N / mm². 2 It is preferable to set it within the range of [this range]. For structures using high-strength reinforcing bars or partially high-strength reinforcing bars, the concrete strength is 45 N / mm². 2 While it is common practice to use high-strength concrete as described above, using high-strength concrete for foundation beam 1 would result in a significant increase in construction costs. In the anchoring structure for the main reinforcement of the foundation beam of the present invention, 24-42 N / mm 2For underground beams 13 using concrete with a certain range of strength, it is possible to use high-strength reinforcing bars or partially high-strength reinforcing bars as main reinforcement, while avoiding lateral spalling failure and allowing the main reinforcement bars to perform to their full potential. This also allows for a reduction in the amount of main reinforcement bars used in the foundation beam while ensuring sufficient anchorage strength. Furthermore, the use of partially high-strength reinforcing bars 21 can contribute to reducing construction costs.

[0020] The method for forming the anchorage structure for the main reinforcement of the foundation beam in the first embodiment shown in Figure 2(A) is, for example, to place the reinforcement by pre-installing nuts 4 on the inside of the ends of the main reinforcement 2 that are located on the surface of the footing 11, filling and hardening concrete, then placing the anchorage steel plate 3 on the surface of the footing 11 and fixing it in place by overlapping the two nuts 4 from the outside.

[0021] Furthermore, the embodiment shown in Figure 2(B) can be formed by, for example, arranging the main reinforcement bars 2 so that their ends are exposed from the surface of the footing 11 of the foundation beam 1, filling and hardening concrete, inserting the anchoring steel plate 3 from the exposed end side of the main reinforcement bars 2, arranging it so that it is in close contact with the surface of the footing 11, and then fixing it using two overlapping nuts 4.

[0022] Furthermore, the method for forming the embodiment shown in Figure 2(C) involves, for example, arranging the main reinforcement bars 2 so that their ends are exposed from the surface of the footing 11 of the foundation beam 1, filling the surface of the footing 11 with concrete to form a recess 6 equal to the thickness of the anchoring steel plate 3 and allowing it to harden, inserting the anchoring steel plate 3 from the exposed end of the main reinforcement bars 2 until it abuts against the recess 6, and then using two nuts 4 to overlap and fix the surface of the footing 11 and the surface of the anchoring steel plate 3 so that they are flush.

[0023] According to the first embodiment of the anchoring structure for the main reinforcement bars of a foundation beam of the present invention, by arranging the anchoring steel plates 3 at the ends of the main reinforcement bars 2 in predetermined positions, the anchoring length and bearing area of ​​the main reinforcement bars 2 can be increased. For this reason, for example, it is possible to use high-strength reinforcing bars or partially high-strength reinforcing bars as the main reinforcement bars 2 in a foundation beam 1 made of ordinary-strength concrete, and the performance of the main reinforcement bars 2 can be fully demonstrated while avoiding lateral spalling failure. Therefore, when high-strength reinforcing bars or partially high-strength reinforcing bars are used as the main reinforcement bars 2, the amount of main reinforcement bars 2 to be placed in the concrete foundation beam 1 can be reduced, and even in this case, sufficient anchoring strength can be ensured.

[0024] <An aspect of the second embodiment (the above structure (B))> Figure 5 is a cross-sectional view illustrating a second embodiment of the anchorage structure for the main reinforcement of a foundation beam according to the present invention.

[0025] In the second embodiment, the main reinforcement bars 2 extending inside the underground beam 13 are inserted into the footing 11, and the anchoring steel plates 3 placed at the ends of the main reinforcement bars 2 are embedded inside the footing 11. The type of main reinforcement bars 2 used, the conditions of the anchoring steel plates 3, and the connection conditions between the main reinforcement bars 2 and the anchoring steel plates 3 are the same as in the first embodiment, so a detailed explanation is omitted.

[0026] The method for forming the anchoring structure of the second embodiment is not particularly limited, but for example, by fixing the anchoring steel plate 3 in advance by sandwiching it between two nuts 4 at the end of the main reinforcement 2, and then filling and hardening concrete, the anchoring steel plate 3 can be positioned at a desired location inside the footing 11.

[0027] In the second embodiment of the present invention relating to the anchoring structure for the main reinforcement of a foundation beam, the anchoring length and bearing area of ​​the main reinforcement 2 can be increased by arranging the anchoring steel plate 3 at the end of the main reinforcement 2 in a predetermined position. For this reason, for example, it is possible to use high-strength reinforcement or partially high-strength reinforcement as the main reinforcement 2 for a foundation beam 1 made of ordinary-strength concrete, and the performance of the main reinforcement 2 can be fully demonstrated while avoiding lateral spalling failure. Therefore, when high-strength reinforcement or partially high-strength reinforcement is used as the main reinforcement 2, the amount of main reinforcement to be placed in the concrete foundation beam 1 can be reduced, and even in this case, sufficient anchoring strength can be ensured.

[0028] <Example 1 including the first and / or second embodiments> Figure 6 is a cross-sectional view showing an example including the first and / or second embodiment of the anchorage structure for the main reinforcement of a foundation beam according to the present invention.

[0029] The embodiment illustrated in Figure 6(a) corresponds to the first embodiment shown in Figure 1.

[0030] The configuration illustrated in Figure 6(b) is a structure in which the main reinforcement bars 2 extending inside the underground beam 13 are inserted into the interior of the foundation column 12 and the footing 11, and the anchoring steel plates 3 are embedded inside the foundation column 12 and the footing 11 (second embodiment).

[0031] The configuration illustrated in Figure 6(c) is a structure in which the main reinforcement bars 2 extending inside the underground beam 13 penetrate the inside of the foundation column 12 and the footing 11, and the anchoring steel plate 3 abuts against the surface of the foundation column 12 and the footing 11, and furthermore, this anchoring steel plate 3 is covered by an additional concrete pouring section 5 (additional concrete pouring section) (modified version of the first embodiment). By forming the additional concrete pouring section 5, corrosion of the main reinforcement bars 2 can be suppressed.

[0032] The configuration illustrated in Figure 6(d) includes a structure in which the upper main reinforcement bars 2 extending inside the underground beam 13 penetrate the inside of the foundation column 12, the anchoring steel plates 3 at the ends of these main reinforcement bars 2 abut against the surface of the foundation column 12, and furthermore, these anchoring steel plates 3 are covered by the additional concrete pouring portion 5 (modification of the first embodiment). Furthermore, the configuration illustrated in Figure 6(d) includes a structure in which the lower main reinforcement bars 2 extending inside the underground beam 13 are inserted into the inside of the footing 11, and the anchoring steel plates 3 are embedded inside the footing 11 (second embodiment).

[0033] The configuration illustrated in Figure 6(e) includes a structure in which the upper main reinforcement bars 2 extending inside the underground beam 13 penetrate the inside of the foundation column 12, and the anchoring steel plates 3 at the ends of these main reinforcement bars 2 abut against the surface of the foundation column 12 (first embodiment). Furthermore, the configuration illustrated in Figure 6(e) includes a structure in which the lower main reinforcement bars 2 extending inside the underground beam 13 are inserted into the inside of the footing 11, and the anchoring steel plates 3 are embedded inside the footing 11 (second embodiment).

[0034] The configuration illustrated in Figure 6(f) includes a structure in which the upper main reinforcement bars 2 extending inside the underground beam 13 are inserted into the foundation column 12, and the anchoring steel plates 3 are embedded inside the foundation column 12 (second embodiment). Furthermore, the configuration illustrated in Figure 6(f) includes a structure in which the lower main reinforcement bars 2 extending inside the underground beam 13 penetrate the footing 11, and the anchoring steel plates 3 at the ends of these main reinforcement bars 2 are in contact with the surface of the footing 11 (first embodiment).

[0035] In the configuration illustrated in Figure 6(g), the surface (side) of the foundation column 12 and the surface (side) of the footing 11 are formed flush. The upper main reinforcement bars 2 extending inside the underground beam 13 penetrate the inside of the foundation column 12, and the lower main reinforcement bars 2 extending inside the underground beam 13 penetrate the inside of the footing 11. Furthermore, the configuration illustrated in Figure 6(g) includes a structure in which a single anchoring steel plate 3 provided at the ends of the upper and lower main reinforcement bars 2 abuts against the surface (side) of the foundation column 12 and the surface (side) of the footing 11 (first embodiment).

[0036] In the first and second embodiments or their variations illustrated in Figure 6, sufficient anchorage strength can be ensured even when the amount of main reinforcement placed in the concrete foundation beam 1 is reduced. Furthermore, even when high-strength reinforcing bars or partially high-strength reinforcing bars are used as main reinforcement bars 2 in a foundation beam 1 made of ordinary-strength concrete, it is possible to fully utilize the performance of the main reinforcement bars 2 while avoiding lateral spalling failure. In addition, by using partially high-strength reinforcing bars 21 as main reinforcement bars 2, it is possible to improve anchorage strength and reduce costs.

[0037] <Example 2 of the First and / or Second Embodiments> The anchoring structure for the main reinforcement bars of a foundation beam according to the present invention includes configurations in which one anchoring steel plate is provided for a group of two or more main reinforcement bars, and configurations in which one anchoring steel plate is provided for a single main reinforcement bar. In particular, the anchoring structure for the main reinforcement bars of a foundation beam according to the present invention is preferably configured in which one anchoring steel plate is provided for a group of two or more main reinforcement bars. This improves the anchoring strength of the main reinforcement bars, and even when high-strength reinforcement bars or partially high-strength reinforcement bars are used as main reinforcement bars, the performance of the main reinforcement bars can be fully demonstrated while avoiding lateral spalling failure.

[0038] Specifically, examples include a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars consisting of two main reinforcement bars 2, as shown in the embodiment in Figure 3; a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars 2, as shown in Figure 7(a); a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars consisting of four main reinforcement bars 2, as shown in Figure 7(b); a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars consisting of six main reinforcement bars 2, as shown in Figure 7(c); a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars consisting of twelve main reinforcement bars 2, as shown in Figure 7(d); and a configuration in which one anchoring steel plate 3 is joined to a group of main reinforcement bars consisting of twenty-four main reinforcement bars 2, as shown in Figure 7(e). Figure 7(e) is a configuration similar to the one illustrated in Figure 6(g), in which the surface (side) of the foundation column 12 and the surface (side) of the footing 11 are formed flush, and a single anchoring steel plate 3 provided at the ends of the upper and lower main reinforcement bars 2 abuts against the surface (side) of the foundation column 12 and the surface (side) of the footing 11.

[0039] Furthermore, as shown in Figures 7(a) to 7(e), in addition to a configuration in which the reinforcement is divided into upper and lower main reinforcement groups and a fixing steel plate 3 is joined to each, it is also possible to have a configuration in which one fixing steel plate 3 is joined to each of the intermediate main reinforcement groups between the upper and lower main reinforcement groups, as shown in Figure 7(f). Note that the above configurations can be applied to any of the first embodiment, the second embodiment and its modifications, and combinations thereof.

[0040] Furthermore, in the first embodiment, as shown in Figure 7(e), when a configuration is used in which large anchoring steel plates 3 are joined, the anchoring steel plates 3 can also be used as formwork when pouring concrete. When using the anchoring steel plates 3 as formwork in this way, they can function as part of the formwork by fixing the anchoring steel plates 3 to predetermined positions at the ends of the main reinforcement bars 2 in advance before pouring concrete.

[0041] The anchoring structure for the main reinforcement of the foundation beam of the present invention has been described above based on embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

[0042] For example, in the above embodiment, the main reinforcement bars 2 arranged horizontally were described as the anchorage structure for the main reinforcement of the foundation beam 1, but this can also be applied to main reinforcement bars arranged in directions other than horizontal, such as vertically in the foundation column 12 and footing 11. [Explanation of symbols]

[0043] 1 Foundation beam 11 Footing 12 Foundation Columns 13 Underground beam 2 Main reinforcement 21 Partially high-strength reinforcing bars 3. Fixing steel plate 4 nuts 5. Additional coating section 6 recesses

Claims

1. An anchoring structure for main reinforcement used in the foundation beams of concrete structures, The aforementioned foundation beam includes underground beams, foundation columns, and footings. A plate-shaped anchoring steel plate is provided at the end of the main reinforcement bar. The main reinforcement is either high-strength reinforcement or partial high-strength reinforcement. Structures A and B below: (Structure A) A structure in which the anchoring steel plate is in contact with at least one of the surfaces of the foundation column and the footing. (Structure B) A structure in which the anchoring steel plate is embedded inside at least one of the foundation column and the footing. An anchoring structure for the main reinforcement of a foundation beam, characterized by including at least one of the following.

2. The anchoring structure for the main reinforcement bars of a foundation beam according to claim 1, characterized in that one anchoring steel plate is provided for a group of main reinforcement bars consisting of two or more of the main reinforcement bars.

3. The concrete strength of the aforementioned underground beam is 24 to 42 N / mm². ２ The anchoring structure for the main reinforcement of the foundation beam according to claim 1, characterized in that it is within the range of [specified range].

4. The anchoring structure for the main reinforcement of a foundation beam according to claim 1, characterized in that the thickness of the anchoring steel plate is in the range of 8 to 45 mm.

5. The anchoring structure for the main reinforcement of a foundation beam according to claim 1, characterized in that, in the structure A, at least one of the anchoring steel plates is covered by an additional concrete portion provided on the surface of the foundation column or the footing.

6. The anchoring structure for the main reinforcement of a foundation beam according to claim 1, characterized in that the anchoring steel plate functions as formwork when concrete is poured.

Images