Reinforcing structure for concrete structure and reinforcing method for concrete structure

Abstract

To provide a reinforcing structure of a concrete structure capable of suppressing reduction in yield strength caused by joining reinforced concrete members to each other.SOLUTION: A reinforcing structure of a concrete structure 1, in which a first concrete member 10 and a second concrete member 20 are joined by an anchor 40 straddling in an axial direction, comprises: a first long member 11 inserted into a plurality of first insertion holes 10h that extend in a vertical direction in the first concrete member 10 and are formed along a direction parallel to a joint surface S formed between the first concrete member 10 and the second concrete member 20; and a first fixture 12 for fixing an end of the first long member 11 inserted into the first insertion hole 10h to the first concrete member 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a reinforcement structure for a concrete structure and a method for reinforcing a concrete structure.

Background Art

[0002] Conventionally, when constructing a concrete structure, a plurality of reinforced concrete members are joined on site. When constructing a beam structure by joining these reinforced concrete members, if a shear force in the vertical (axial) direction acts on the beam structure, there are problems such as a decrease in the bearing capacity or failure at the joint surface compared to a monolithic beam structure without a joint surface between adjacent beam members. Therefore, in the axial direction orthogonal to the vertical direction in which the shear force acts, some reinforcement structure such as connecting the beams on both sides across the joint surface is essential.

[0003] For example, Patent Document 1 discloses a joining structure of reinforced concrete members (precast members) in a concrete structure. A beam as a joining structure of precast members has a pair of left and right precast members and a joining portion for joining the precast members, and a reinforcing bar penetrating one side precast member in the axial direction and a reinforcing bar penetrating the other side precast member in the axial direction are connected in an inclined state at the joining portion.

[0004] By embedding the inclined portions of the reinforcing bars at the joining portion located between the pair of left and right precast members, a vertical resistance force against the shear force is generated in the integrated beam. This resistance force suppresses the vertical displacement of the inclined portion, and can suppress the extrusion of the cover concrete by the axial reinforcing bars.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in the joining structure of Patent Document 1, the reinforcing bars passing through the precast member on one side in the axial direction and the reinforcing bars passing through the precast member on the other side in the axial direction are connected by a connection method such as a lap joint at the joint. Such a connection method such as a joint is applicable to a newly constructed concrete member, but not applicable to an existing concrete member. Therefore, when targeting an existing concrete member, it is conceivable to join using an anchor for post-construction.

[0007] However, when constructing using an anchor, if displacement occurs in the vertical direction at the joint portion, there is a risk of cracks occurring along the anchor due to the anchor pushing out the overlapping concrete in the vertical direction. In such a situation, it is difficult to suppress the reduction in load-bearing capacity caused by joining concrete members together.

[0008] Therefore, an object of the present invention is to provide a reinforcing structure for a concrete structure and a method for reinforcing a concrete structure that can suppress a reduction in load-bearing capacity caused by joining concrete members together.

Means for Solving the Problems

[0009] In response to the above problems, the reinforcing structure of a concrete structure of the present invention is a reinforcing structure of a concrete structure in which a pre-provided first concrete member and a second concrete member newly attached to the first concrete member are joined by a coupling material straddling in the axial direction, and the first concrete member extends in the vertical direction and a first long member inserted into a plurality of first insertion holes formed along a direction parallel to the joint surface formed between the first concrete member and the second concrete member, and a first fixing tool for fixing an end portion of the first long member inserted into the first insertion hole to the first concrete member.

[0010] Here, the first insertion hole is a through hole through which the first long member penetrates the first concrete member in the vertical direction, and it is desirable that the first long member is fixed by the first fixture on the upper and lower surfaces of the first concrete member. Further, the reinforcement structure of the concrete structure desirably includes a second long member inserted into a second insertion hole formed in the second concrete member and penetrating in the vertical direction, and a second fixture for fixing the second long member to the second concrete member on the upper and lower surfaces of the second concrete member.

[0011] Also, it is desirable that the first fixture is a fixture for fixing the tensioned first long member to the surface of the first concrete member, and it is desirable that the first insertion hole is filled with a filler for filling the gap between the first long member.

[0012] The method for reinforcing a concrete structure according to the present invention is a method for reinforcing a concrete structure in which a previously provided first concrete member and a second concrete member newly attached to the first concrete member are joined by a coupling member straddling in the axial direction, and in the first concrete member, an insertion step of inserting a first long member into a plurality of first insertion holes formed along the width direction while extending in the vertical direction, and a fixing step of fixing an end portion of the first long member inserted into the first insertion hole to the first concrete member by a first fixture.

[0013] Here, in the fixing step, it is desirable to fix the tensioned first long member to the surface of the first concrete member by the first fixture.

Effect of the Invention

[0014] The reinforcement structure of the concrete structure of the present invention includes a first long member inserted into a plurality of first insertion holes formed along a direction parallel to a joint surface formed between a first concrete member and a second concrete member while extending in the vertical direction in the first concrete member, and a first fixture that fixes an end portion of the first long member inserted into the first insertion hole to the first concrete member.

[0015] Therefore, it is possible to improve the vertical strength when a shearing force acts on the concrete structure. Accordingly, it is possible to suppress a decrease in the allowable stress caused by the joint surface formed by joining the concrete members together.

[0016] In particular, the first insertion hole is a through hole through which the first long member penetrates the first concrete member in the vertical direction, and the first long member is fixed by the first fixture on the upper surface and the lower surface of the first concrete member. Thereby, the shearing force acting on the first concrete member can be suppressed from both above and below. Accordingly, when the first long member is fixed by the first fixture on the upper surface and the lower surface of the first concrete member, it is possible to suppress the possibility of cracking occurring in the first concrete member.

[0017] Further, it includes a second long member inserted into a second insertion hole penetrating in the vertical direction formed in the second concrete member, and a second fixture that fixes the second long member to the second concrete member on the upper surface and the lower surface of the second concrete member. Thereby, the shearing force acting on both sides of the joint surface between the first concrete member and the second concrete member can be suppressed from both above and below. Accordingly, when the second long member is also fixed by the second fixture in the second concrete member, it is possible to improve the allowable stress of the entire concrete structure.

[0018] Here, the first fixture is a fixture for fixing the tensioned first long member to the surface of the first concrete member. In short, since the first long member is fixed to the surface of the first concrete member by the fixture, it can be fixed to the first concrete member in a state where prestress is applied to the first long member.

[0019] Furthermore, the first insertion hole is filled with a filler for filling the gap between the first long member. Thereby, it is possible to suppress water from entering the first insertion hole due to the filler. Therefore, it is possible to suppress the first long member from deteriorating.

[0020] The method for reinforcing a concrete structure according to the present invention includes an insertion step of inserting a first long member into a first insertion hole formed in a plurality along the width direction while extending in the vertical direction in a first concrete member, and a fixing step of fixing an end portion of the first long member inserted into the first insertion hole to the first concrete member by a first fixture.

[0021] For this reason, it is possible to improve the strength in the vertical direction in which the shearing force acts in the concrete structure. Thereby, it is possible to suppress a decrease in the shear strength due to the joint surface formed by joining the concrete members.

[0022] Here, in the fixing step, the tensioned first long member is fixed to the surface of the first concrete member by the first fixture. In short, since the first long member is fixed to the surface of the first concrete member by the fixture, it can be fixed to the first concrete member in a state where prestress is applied to the first long member.

Brief Description of the Drawings

[0023]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the whole reinforcement structure of the concrete structure according to an embodiment of the present invention, FIG. 2 is a perspective view showing another example of the reinforcement structure of the concrete structure, and FIG. 3 is a perspective view showing still another example of the reinforcement structure of the concrete structure. Further, FIG. 4 is an enlarged longitudinal sectional view of an end portion of the first concrete member, and FIG. 5 is an enlarged longitudinal sectional view of an end portion of the second concrete member.

[0025] As shown in FIG. 1, the concrete structure 1 is configured as a beam structure in which the first concrete member 10 and the second concrete member 20 are joined. The first concrete member 10 is a previously provided portion, and the second concrete member 20 is a member newly provided with respect to the first concrete member 10. Note that the second concrete member 20 may be a precast concrete member.

[0026] Note that although both the first concrete member 10 and the second concrete member 20 are beam-shaped members formed in a long shape, they are not limited to this. As long as a joint surface S is formed between the first concrete member 10 and the second concrete member 20, various shapes such as beam shape and flat plate shape can be considered. Further, although both the first concrete member 10 and the second concrete member 20 are provided as members constituting a beam, they are not necessarily limited to this.

[0027] A joint surface S is formed at the joint portion between the first concrete member 10 and the second concrete member 20. As shown in FIG. 4, a first end face 10c is formed on one end side of the first concrete member 10, and a second end face 20c is formed on one end side of the second concrete member 20. The portion where the first end face 10c and the second end face 20c are in contact is defined as the joint surface S.

[0028] In the concrete structure 1, the first concrete member 10 and the second concrete member 20 are joined by an anchor (bonding material) 40 straddling in their axial direction (extending direction). That is, as shown in FIG. 1, the anchor 40 is inserted through the joint surface S into the first concrete member 10 and the second concrete member 20, and the anchor 40 joins the first concrete member 10 and the second concrete member 20.

[0029] In the first concrete member 10, a first long member 11 is inserted into a first insertion hole 10h formed along a direction extending in the vertical direction and parallel to the joint surface S. Specifically, as shown in FIG. 4, on the first end face 10c side of the first concrete member 10, a first insertion hole 10h extending in the vertical direction parallel to the first end face 10c is formed. The first insertion hole 10h is a through hole penetrating the first concrete member 10 in the vertical direction, and the first long member 11 is inserted into the first insertion hole 10h.

[0030] A plurality of first insertion holes 10h are formed along the joint surface S in the first concrete member 10, and the first long member 11 is inserted into each of the first insertion holes 10h.

[0031] The first insertion hole 10h may be filled with a filler 50 that fills the gap between the first long member 11. That is, as shown in FIG. 4, the filler 50 may be filled so as to cover the periphery of the first long member 11 inserted into the first insertion hole 10h.

[0032] In the second concrete member 20, a second long member 21 is inserted into a second insertion hole 20h that extends in the vertical direction and is formed along a direction parallel to the joint surface S. Specifically, as shown in FIG. 5, on the second end face 20c side located on the first concrete member 10 side of the second concrete member 20, a second insertion hole 20h that extends in the vertical direction parallel to the second end face 20c is formed. The second insertion hole 20h is a through hole that penetrates the second concrete member 20 in the vertical direction, and the second long member 21 is inserted into the second insertion hole 20h.

[0033] A plurality of second insertion holes 20h are formed in the second concrete member 20 in a direction parallel to the joint surface S, and the second long member 21 is inserted into each second insertion hole 20h.

[0034] The second insertion hole 20h may be filled with a filler 50 that fills the gap between the second long member 21. That is, as shown in FIG. 5, the filler 50 may be filled so as to cover the periphery of the second long member 21 inserted into the second insertion hole 20h.

[0035] Both the first long member 11 and the second long member 21 are members that extend linearly and are formed of a high-rigidity material such as iron. It is desirable that the first long member 11 and the second long member 21 be reinforcing bars (D25) having a diameter of about 25 mm, for example.

[0036] The first insertion hole 10h and the second insertion hole 20h may be formed at the same distance from the joint surface S, or may be formed at different positions. The number of the first insertion holes 10h and the second insertion holes 20h may be the same or different. When a plurality of the first insertion holes 10h and the second insertion holes 20h are formed at equal intervals from the joint surface S at the same distance, the load can be evenly applied to the left and right sides of the joint surface S in the concrete structure 1.

[0037] Also, in the second concrete member 20, the second insertion hole 20h does not necessarily have to be formed. That is, as shown in FIG. 2, in the concrete structure 1A, the first concrete member 10 into which the first long member 11 is inserted and the second concrete member 20 in which the second insertion hole 20h is not formed and the second long member 21 is not inserted may be joined.

[0038] Also, for example, as shown in FIG. 3, in the concrete structure 1B, when the first concrete member 10A has a protruding portion 13 protruding downward and the first concrete member 10A is formed in an L shape in side view, the first long member 11 does not have to penetrate the protruding portion 13.

[0039] The first concrete member 10 is provided with a first fixture 12 for fixing the end portion of the first long member 11 inserted into the first insertion hole 10h to the first concrete member 10. Specifically, as shown in FIG. 4, the first fixture 12 is provided at a position overlapping the first insertion hole 10h in a portion of the upper surface 10a and the lower surface 10b of the first concrete member 10 on the side of the first end surface 10c.

[0040] The first fixture 12 is formed in a flat plate shape and the first long member 11 penetrates therethrough. The first fixture 12 is a fixing tool for fixing the tensioned first long member 11 to the upper surface 10a and the lower surface 10b of the first concrete member 10. The first fixture 12 is, for example, a plate-shaped member formed of iron having a thickness of about 30 mm and a fastening member such as a nut provided thereon.

[0041] Further, as shown in FIG. 5, a second fixture 22 is provided at a position overlapping with the second insertion hole 20h in a portion on the second end face 20c side of the upper surface 20a and the lower surface 20b of the second concrete member 20. Since the second fixture 22 has the same configuration as the first fixture 12, a detailed description thereof will be omitted.

[0042] Hereinafter, in order to verify the effect of the reinforcement structure according to the embodiment, numerical analysis was performed using an FEM (Finite Element Method) model which is an analysis model based on the finite element method. FIG. 6 is a schematic diagram of the FEM model. This FEM model is a model in which the concrete structure 1 is replaced with a simple beam model supported by pins at both ends. It is assumed that the joint surface S is formed by being displaced to one side from the central portion.

[0043] Using such an FEM model, for a conventional FEM model based on a simple beam before reinforcement (hereinafter simply referred to as "conventional FEM model") and an FEM model based on a simple beam having the reinforcement structure of the concrete structure 1 according to the embodiment (hereinafter simply referred to as "FEM model according to the embodiment"), the deflection amount when a vertical (vertical) load P is applied to the central portion was calculated.

[0044] FIG. 7 is a graph showing a comparison of the relationship between the load and the deflection in the conventional FEM model and the FEM model according to the embodiment. In FIG. 7, the broken line indicates the relationship between the load and the deflection in the conventional FEM model, and the solid line indicates the relationship between the load and the deflection in the FEM model according to the embodiment.

[0045] When comparing the FEM model according to the embodiment in which the joint portion is reinforced and the conventional FEM model in which the joint portion is not reinforced, when the same load is applied, the yield strength when both sides of the joint surface S are reinforced generally exceeds the yield strength when not reinforced. For example, when a load of about 500 kN was applied to the concrete structure according to the embodiment, a deflection of about 8 mm occurred, whereas when a load of about 500 kN was applied to the conventional concrete structure, a deflection of about 13 mm occurred. That is, when the same load is applied, the amount of deflection of the FEM model according to the embodiment is smaller than that of the conventional FEM model, and thus it can be seen that the yield strength of the FEM model according to the embodiment is improved.

[0046] FIG. 8(a) is a contour diagram showing the distribution of the horizontal component of the strain generated in the conventional FEM model, and FIG. 8(b) is a contour diagram showing the distribution of the vertical component of the strain generated in the conventional FEM model. FIG. 9(a) is a contour diagram showing the distribution of the horizontal component of the strain generated in the FEM model according to the embodiment, and FIG. 9(b) is a contour diagram showing the distribution of the vertical component of the strain generated in the FEM model according to the embodiment. Each figure shows the maximum principal strain when the maximum load is applied to the concrete structure 1.

[0047] In the conventional FEM model shown in FIGS. 8(a) and 8(b), it can be seen that the amount of strain in the joint portion (joint surface S) between the first concrete member 10 and the second concrete member 20 is larger than that in the FEM model according to the embodiment shown in FIGS. 9(a) and 9(b). This is considered to be because in the concrete structure 1 according to the embodiment, both sides of the joint surface S are reinforced by the reinforcing structure, so that the yield strength is improved on both sides of the joint surface S, and as a result, the strain is suppressed.

[0048] Here, the region X circled in FIGS. 8(a) and 9(a) and the region Y circled in FIGS. 8(b) and 9(b) both indicate the range including the joint surface S and its surrounding region in the concrete structure 1. As can be seen in regions X and Y, it can be understood that in the FEM model according to the embodiment, compared with the conventional FEM model, the strain amount is significantly reduced and the load-bearing capacity is improved.

[0049] As described above, when the same load is applied, the deflection amount of the conventional concrete structure 1 is larger than that of the concrete structure according to the embodiment. This shows that the load-bearing capacity of the concrete structure 1 according to the embodiment has been improved.

[0050] Thus, the reinforcement structure of the concrete structure 1 of the present invention includes a first long member 11 that extends in the vertical direction in the first concrete member 10 and is inserted into a plurality of first insertion holes 10h formed along a direction parallel to the joint surface S formed between the first concrete member 10 and the second concrete member 20, and a first fixture 12 that fixes the end of the first long member 11 inserted into the first insertion hole 10h to the first concrete member 10.

[0051] Therefore, the vertical strength when a shearing force acts on the first concrete member 10 can be improved. Accordingly, it is possible to suppress a decrease in the load-bearing capacity caused by the joint surface S formed by joining the first concrete member 10 and the second concrete member 20.

[0052] In particular, the first insertion hole 10h is a through hole through which the first long member 11 penetrates the first concrete member 10 in the vertical direction, and the first long member 11 is fixed by the first fixture 12 on the upper surface 10a and the lower surface 10b of the first concrete member 10. Thereby, the shearing force acting on the first concrete member 10 can be suppressed from both above and below. Therefore, when the first long member 11 is fixed by the first fixture 12 on the upper surface 10a and the lower surface 10b of the first concrete member 10, the possibility of cracking in the first concrete member 10 can be suppressed.

[0053] Also provided are a second long member 21 inserted into a second insertion hole 20h formed in the second concrete member 20 and penetrating in the vertical direction, and a second fixture 22 that fixes the second long member 21 to the second concrete member 20 on the upper surface 20a and the lower surface 20b of the second concrete member 20. Thereby, it is possible to appropriately resist the shearing force acting in the vertical direction on both sides of the joint surface S between the first concrete member 10 and the second concrete member 20. Therefore, when the second long member 21 is also fixed by the second fixture 22 in the second concrete member 20, the load-bearing capacity of the entire concrete structure 1 can be improved.

[0054] Here, the first fixture 12 is a fixture for fixing the tensioned first long member 11 to the surface of the first concrete member 10. In short, since the first long member 11 is fixed to the surface of the first concrete member 10 by the fixture, it can be fixed to the first concrete member 10 in a state where prestress is applied to the first long member 11.

[0055] Furthermore, the first insertion hole is filled with a filler 50 that fills the gap between the first long member 11. In short, the filler 50 suppresses water from entering the first insertion hole 10h. Therefore, it is possible to suppress the deterioration of the first long member 11.

[0056] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are included in the present invention.

Explanation of Reference Numerals

[0057] 1: Concrete structure 10: First concrete member 10h: First insertion hole 11: First long member 12: First fixture 20: Second concrete member 20h: Second insertion hole 21: Second long member 22: Second fixture 40: Anchor S: Joint surface

Claims

1. A reinforcing structure for a concrete structure in which a pre-provided first concrete member and a second concrete member newly attached to the first concrete member are joined by a coupling material spanning in the axial direction, a first long member inserted into a plurality of first insertion holes formed along a direction parallel to a joint surface formed between the first concrete member and the second concrete member while extending in the vertical direction in the first concrete member, and a first fixture for fixing an end portion of the first long member inserted into the first insertion hole to the first concrete member. A reinforcing structure for a concrete structure is characterized by comprising the same.

2. The first insertion hole is a through hole through which the first long member penetrates the first concrete member in the vertical direction, and the first long member is fixed by the first fixture on the upper surface and the lower surface of the first concrete member. The reinforcing structure for a concrete structure according to claim 1 is characterized by this.

3. a second long member inserted into a second insertion hole penetrating in the vertical direction formed in the second concrete member, and a second fixture for fixing the second long member to the second concrete member on the upper surface and the lower surface of the second concrete member. The reinforcing structure for a concrete structure according to claim 1 or 2 is characterized by comprising the same.

4. The first fixture is a fixture for fixing the tensioned first long member to the surface of the first concrete member. The reinforcing structure for a concrete structure according to claim 1 or 2 is characterized by this.

5. The first insertion hole is filled with a filling material for filling a gap between the first long member. The reinforcing structure for a concrete structure according to claim 1 or 2 is characterized by this.

6. A method for reinforcing a concrete structure in which a pre-provided first concrete member and a second concrete member newly attached to the first concrete member are joined by a coupling material spanning in the axial direction, an insertion step of inserting a first long member into a plurality of first insertion holes formed along the width direction while extending in the vertical direction in the first concrete member, and a fixing step of fixing an end portion of the first long member inserted into the first insertion hole to the first concrete member by a first fixture. A method for reinforcing a concrete structure is characterized by comprising the same.

7. The method for reinforcing a concrete structure according to claim 6, wherein in the fixing step, the tensioned first long member is fixed to the surface of the first concrete member by the first fixture.

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