JP2868994B2 - Concrete joint structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete joint structure in an RC concrete structure or the like.

[0002]

2. Description of the Related Art In RC concrete structures and the like,
Generally, as shown schematically in FIG. 4, first, the bottom plate concrete 15 is cast and hardened, and then the concrete of the side wall 2 is cast and hardened to form the side wall 2. However, since the amount of shrinkage of the side wall 2 after curing and the amount of shrinkage of the bottom plate 15 after curing are different from each other, the deformation (shrinkage) of the side wall 2 is restricted by the bottom plate 15, and as a result, the side wall 2 is cracked. 16 occurs. Water or the like invades from the cracks 16 to corrode the reinforcing steel inside the side wall 2 or cause cracks 1
6 causes water leakage.

It is difficult to prevent the occurrence of the cracks 16 themselves. For this reason, recently, cracks 16
Rather than preventing itself, a technique for generating cracks 16 so as not to lower the durability is considered to be promising. From this point of view, a technique is employed in which the cross-section defects are provided at predetermined intervals in the side wall 2 and the cracks 16 are concentrated at predetermined locations. In the case of a watertight structure, it is necessary to take appropriate measures against water stoppage, such as burying a water stoppage plate in concrete in advance.

FIG. 5 shows a side wall 2 provided with a crack-inducing joint.
Is a cross-sectional view taken along the width direction. Grooves 4 are provided on the surface of the side wall 2 at predetermined intervals. A pair of members 17 for deficient cross-section is buried inside the portion where the groove 4 exists. Each of the cross-section deficient members 17 has a flat plate shape, and is substantially aligned when viewed in cross section. In the case of a watertight structure, a water stoppage plate 18 is further embedded between a pair of members 17 for section loss. Each member 17 for section loss is fixed to a steel plate 20 for mounting, and a water stop plate 18 is fixed to a reinforcing bar 19 for mounting. Thereby, when the member 17 for sectional loss and the water stop plate 18 pour the concrete material into the formwork,
Avoid deformation.

[0005] A pair of cross-section deficient members 17 and grooves 4 play a role of cross-section deficiency. Assuming that the thickness of the side wall 2 made of concrete is 100, it is said that the total of the lengths of the member 17 for cross-sectional defect and the groove 4 is required to be 20 to 30 or more. Thereby, when stress is applied to the side wall 2 due to the difference in the amount of contraction between the bottom plate and the side wall, cracks 16A and 16B are generated along the groove 4 and the member 17 for section loss. At this time, since the crack 16A appears in the groove 4, the crack 1
6A is hard to be seen from the outside of the side wall 2 and cracks 16A
But hardly noticeable. Each of the cracks 16 </ b> A and 16 </ b> B generated along the cross-sectional defect member 17 is divided by the water stop plate 18. Therefore, cracks 16A or 16B
The intruded water transmitted from is stopped by the water stop plate 18, so that water leakage can be prevented.

[0006]

However, the outside air and moisture entering from the surface of the concrete are cracked 16A,
Since the steel reaches the reinforcing bar 3 through 16B, corrosion of the reinforcing bar 3 is promoted.

Further, the crack 16A is substantially linearly generated along the shortest distance between the groove 4 and the end of the member 17 for section loss. In this case, the crack 16A is hidden in the groove 4. However, the member 17 for section loss and the groove 4
The cracks do not always occur linearly between the two, and in some cases, like the cracks 16B, the cracks 16B may appear on the outer wall of the side wall 4. In this case, since the aesthetic appearance of the side wall 2 is impaired, it is necessary to repair the outer wall surface.

[0008] Further, when the concrete is poured, the member 17 for deficient section is formed by the pressure of the flowing concrete.
And so that the water stop plate 18 does not shift or deform
It is necessary to weld the member 17 for sectional loss to the steel plate 20 for mounting, and to weld the water blocking plate 18 to the reinforcing bar 19 for mounting. For this reason, it took a lot of time and effort to attach each joint member.

An object of the present invention is to provide a concrete structure of a crack-inducing type comprising a structural reinforcing bar, a structure made of concrete, a groove provided on the surface side of the structure, and a member for lacking a cross section. An object of the present invention is to prevent corrosion of a structural reinforcing bar due to outside air and moisture entering from the surface of concrete in a joint structure.

[0010] Another object of the present invention is to ensure that cracks are generated in grooves.

[0011]

According to the present invention, there is provided a joint structure for concrete comprising: a structural rebar; a concrete structure cast so as to include the structural rebar;
A groove provided on the surface side of the structure, and a member for cross-sectional defect disposed between the groove and the structural reinforcing bar, wherein the member for cross-sectional defect is a plate-shaped core material. And a pressure-sensitive adhesive layer made of a polymer material that is in close contact with the concrete, and the core material has a protruding portion that protrudes in a triangular chevron, and It has a flat plate-shaped flange portion extending on both sides, and the protruding portion faces the groove.

[0012]

According to the present invention, in the above-described crack-inducing type concrete joint structure, the member for section loss is arranged between the groove of the structure and the structural reinforcing bar. The distance between the member and the member is much smaller than before, and cracks are surely generated from the groove toward the member for sectional loss. Therefore, the appearance of the structure is not impaired by the crack.

[0013] Moreover, since the member for cross-sectional deficiency is provided with a core material and an adhesive layer made of a polymer material that adheres to concrete, even if outside air and water enter from cracks,
Outside air and water are blocked at the interface between the adhesive layer and the concrete. Therefore, the life of the structural reinforcing bar can be extended since the structural reinforcing bar is not exposed to the outside air and water.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, in a cross-section of the member for cross-section deficiency cut in the width direction of the structure, the member for cross-section deficiency is provided with a protruding portion, and the protruding portion faces the groove. . As a result, the distance between the groove and the member for section loss is further reduced, and an internal stress is applied along the shape of the protruding portion, so that a crack is easily formed from the protruding portion toward the groove.

In the present invention, preferably, a through hole is formed in the member for cross-sectional loss, and a binding wire is inserted into the through-hole. Tied up against. Thereby, unlike the case of welding the member for sectional loss, the member for sectional loss can be easily fixed in a short time.

As the adhesive layer made of a polymer material which adheres to concrete, it is particularly preferable to use an adhesive layer made of butyl rubber adhered to a core material. This is because the butyl rubber-based pressure-sensitive adhesive has high adhesiveness to concrete.

The core material of the member for lacking a cross section must have a rigidity that is not deformed by flowing concrete when the concrete is poured. Specifically, rigid materials such as metal, hard rubber, and hard plastic can be exemplified.

It is said that the total of the lengths of the cross-section deficient member and the groove should be at least 20% to 30% of the thickness of the structure. At this point, if the total length of the groove 4 and the above-mentioned member for section loss is insufficient, the member for inner section loss can be further embedded inside the structural reinforcing bar.

From the viewpoint of securing the length necessary for the cross-sectional defect, the member for the internal cross-sectional defect is sufficient if it is embedded as a foreign substance. However, since cracks also occur along the member for losing the inner cross section, from the viewpoint of more completely preventing water leakage or the like from the crack, at least a protruding portion extending in the width direction of the member for losing the inner cross section is used. It is preferable to form the above-mentioned adhesive layer and cover the core material.

A through-hole is also provided in the member for losing the inner cross-section, and a binding wire is inserted into the through-hole, and the member for losing the inner cross-section can be tied to the structural reinforcing bar by the binding wire. The member for deficient inner cross section can be easily fixed in a short time.

The above-mentioned member for section loss and the member for section loss inside are provided with a pair of flange portions. Preferably, each flange portion is fixed to a structural reinforcing bar. As a result, the member for internal cross-section defect and the member for cross-sectional defect are securely fixed to the structural rebar at two locations, respectively, so that when the concrete is poured, the member for cross-sectional defect is less likely to move and deform. Become.

FIG. 1 is a sectional view showing a joint structure according to an embodiment of the present invention, FIG. 2 (a) is a perspective view showing a member 5 for section loss, and FIG. It is a perspective view which shows the member 6 for sectional loss.

In the member 5 for section loss, the protruding portion 5
b has a substantially triangular chevron shape, and elongated plate-like flange portions 5a, 5c are provided on both sides of the protruding portion 5b, respectively.
Are formed. Projecting portion 5b and flange portion 5
The entirety of a and 5c is formed by a core material 9, and of the core material 9, a mountain-shaped protruding portion 5b and a flange portion 5a.
5c is covered with the adhesive layer 10.

In the member 6 for deficient inner cross section, the protruding portion 6b has a flat plate shape, and elongated plate-like flange portions 6a, 6c are provided on both sides of the protruding portion 6b.
Are formed. Projecting portion 6b and flange portion 6
The whole of a and 6c is formed by the core material 13,
The protruding portion 6b of the flat plate shape in the core material 13 is
2 coated.

Each of the flange portions 5a of the member 5 for section loss,
5c, a plurality of through holes 11 are provided, respectively, and a binding wire 7 is inserted through these through holes 11, and the member 5 for cross-sectional loss is connected to the structural reinforcing bar 3 by the binding wire 7. Tied up. Internal cross-section defect member 6
Each of the flange portions 6a and 6c is provided with a plurality of through-holes 11, and the binding wires 7 are inserted into these through-holes 11. It is tied to the steel rebar 8.

Between the groove 4 provided on the surface side of the side wall 2 and the structural reinforcing bar 3, that is, the covering portion 2b of the structural reinforcing bar 3
, A member 5 for deficient cross-section is arranged. The projecting portion 5 b of the member 5 for section loss faces the groove 4. As a result,
The member 5 for section loss exists in the covering area 1 of the structural reinforcing bar 3.

The member 6 for removing an inner cross section is mounted on the opposite side of the member 5 for removing a cross section, and as a result, is present in the inner portion 2 a of the structural reinforcing bar 3. The protruding portion 6b of the member for deficient inner cross section 6 extends substantially in the horizontal direction in FIG. By covering the protruding portion 6b with an adhesive layer, this portion is brought into close contact with concrete.

FIG. 3 is a cross-sectional view showing another member 14 for lacking a cross section. The member 14 for deficient cross-section includes one linear flange portion 14a and a linear projecting portion 14b. The flange portion 14a and the protruding portion 14b are substantially perpendicular to each other. With the protruding portion 14b,
The core 21 is covered with the adhesive layer 20.

[0029]

According to the present invention, in the above-described joint structure of the crack-inducing type concrete, the cracks are surely generated from the groove toward the member for section loss. Therefore, the appearance of the structure is not impaired by the crack. Moreover, even if outside air and water enter from the cracks, the outside air and water do not expose the structural reinforcing bar to the outside air and water, so that the life of the structural reinforcing bar can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a joint structure according to an embodiment of the present invention.

FIG. 2A is a perspective view showing a member for sectional loss 5, and FIG. 2B is a perspective view showing a member for sectional loss 6;

FIG. 3 is a cross-sectional view showing another member for cross-sectional defect 14;

FIG. 4 is a perspective view schematically showing a state where a side wall 2 is cast on a bottom plate 15;

FIG. 5 is a sectional view showing a conventional joint structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Covering area of structural reinforcing bar 2 Side wall 2a Inner part of structural reinforcing bar 2b Covering portion of structural reinforcing bar 3 Structural reinforcing bar 4 Groove 5, 14 Cross-sectional defect member 5a, 5c, 6a, 6c, 14a Flange portion 5b, 6b, 14b Protruding part 6 Inner cross-section deficient member 7 Binding wire 8 Mounting rebar 9, 13, 21 Core material 10, 12, 20 Adhesive layer 11 Through hole 15 Bottom plate 16, 16A, 16B Crack 17 Cross-sectional deficient member 18 Water stop plate

Claims (2)

(57) [Claims] 1. A structural member made of concrete laid so as to include a structural reinforcing bar, a structural reinforcing bar, a groove provided on a surface side of the structural member, and a groove provided on the surface side of the structural member. A member for cross-sectional defect disposed between the reinforcing bar and the reinforcing bar, and the member for cross-sectional defect includes a plate-shaped core material and an adhesive layer made of a polymer material that adheres to the concrete, When the member for cross-sectional loss is viewed in a cross-section, the core material includes a protruding portion protruding in a triangular chevron and a flat plate-shaped flange portion extending on both sides of the protruding portion,
The joint structure of concrete, wherein the protruding portion faces the groove. 2. A through-hole is provided in the member for cross-sectional loss, and a binding wire is inserted into the through-hole.
The joint structure for concrete according to claim 1, wherein the member for section loss is bound to the structural reinforcing bar by the binding wire.