JP6902125B2 - Joint structure of structure - Google Patents

Description

The present invention relates to a joint structure of concrete and mortar, concrete and steel, or a structure having increased shear resistance at the interface between concrete.

As shown in FIG. 5, when a structure 10 made of concrete on one side and a structure 11 made of concrete or mortar on the other side are simply joined by jointing, stress is transmitted between the two structures. It is difficult, and when a shearing force acts during an earthquake, reciprocal displacement (deviation) occurs on the boundary surface 12 of both structures.

Therefore, conventionally, as shown in FIG. 6A, the stress transmission mechanism is configured by burying the dowel 13 between the two structures 10 and 11 so as to be orthogonal to the boundary surface 12. Further, instead of the dowel 13, there was also one in which deformed reinforcing bars were arranged orthogonally to the boundary surface (Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-227761

In the prior art, when the dowel 13 is embedded orthogonally to the boundary surface, the relative displacement of the two structures 10/11 is smaller than that of the frictional joint, but as shown in FIG. 6B, the dowel 13 itself However, the shearing force may cause bending deformation at the interface, and it was not possible to reliably prevent the relative displacement of the two structures 10/11.

On the other hand, in Patent Document 1, a large-diameter portion made of a columnar steel material is provided between a pair of deformed reinforcing bars as an anchor, and the large-diameter portion is buried across the boundary surface, so that stress is transmitted more than a dowel. Performance can be improved. However, since the cross-sectional area of the large diameter portion is smaller than the boundary area of the two structures, it is necessary to arrange a large number of anchors in order to reliably transfer stress over the entire boundary surface. On the other hand, when the anchor is applied to a structure such as a wall slab or a floor slab whose thickness is relatively smaller than that of a column or a beam, there is an increased risk that the wall slab or the like will adhere and break from a large diameter portion due to shearing force.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is a structure having higher shear resistance than arranging dowels or deformed reinforcing bars orthogonally to a boundary surface in two structures. The purpose is to disclose the joint structure of the body.

In order to achieve the above-mentioned object, in the present invention, one of the two structures to be joined is made of concrete or mortar, and a rib provided between the two structures along the longitudinal axis is used. A means was used in which deformed reinforcing bars having knots provided at equal intervals were arranged in parallel with the boundary surface of the two structures, and shear resistance was given by the adhesive stress and bearing stress of the deformed reinforcing bars.

According to this means, stress is transmitted between two structures by the adhesive stress and bearing stress of the deformed reinforcing bar, and high shear resistance is exhibited at the interface between the two structures.

On the other hand, when the other structure is made of steel, the end face to be joined to one structure can be fixed by bonding or welding the cut surface of the half-split deformed reinforcing bar obtained by cutting the steel bar for reinforced concrete in the axial direction. In this case, the cut surface of the half-split deformed reinforcing bar is fixed to the end face of the other structure, and the half-split deformed reinforcing bar is embedded in the one structure. In this case, a half-split deformed reinforcing bar constitutes a stress transmission mechanism to one structure, and the steel material side transmits stress by adhesive stress or welding stress.

By forming the interface between the two structures so as to be parallel to the direction of the shear force during an earthquake, stress transmission by the deformed reinforcing bar is more reliable, and higher shear resistance can be exhibited.

According to the present invention, since the deformed reinforcing bars are arranged in parallel with the boundary surface between the two structures, the stress transmission and the relative displacement prevention between the structures are ensured by the adhesive stress and the bearing stress of the deformed reinforcing bars. Can be done.

Example of joining two structures to which the present invention is applied Explanatory drawing showing an example of a deformed reinforcing bar Sectional drawing which shows 1st Embodiment of this invention Sectional drawing which shows the 2nd Embodiment of this invention Explanatory drawing showing a conventional joint structure Explanatory drawing showing a conventional joining structure using a dowel

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an example of joining two structures to which the present invention is applied. FIG. 1A shows a floor slab 1 and a wall slab 2, (b) wall slabs 2 and 2, and (c) a floor slab 1.・ It is a combination of 1s. The joint structure of the present invention is configured by arranging deformed reinforcing bars 4 in parallel with the boundary surface 3 at the joint portion of the floor slab 1 and the wall slab 2.

As shown in FIG. 2, the deformed reinforcing bar 4 used has ribs 4a formed on the outer periphery of the steel bar for reinforced concrete along the longitudinal axis, and nodes 4b formed at equal intervals. In the illustrated example, the semicircular knots 4b are formed by shifting the upper half and the lower half by half a pitch, but the knots may be formed by forming circular knots at equal intervals. Further, it may have a spiral node formed.

FIG. 3 shows an embodiment of the present invention, in which one structure 5 is made of concrete and the other structure 6 is also made of concrete. Then, between these two structures 5 and 6, a deformed streak 4b shown in FIG. 2 is embedded in parallel with the boundary surface (joint surface).

According to the joint structure, when shear forces in opposite directions act on each of the two structures 5 and 6, the adhesive stress between the nodes 4b and the support of the nodes 4b are applied to the upper half and the lower half of the deformed reinforcing bar 4, respectively. Pressure stress is generated in the direction opposite to the shearing force, and this shearing resistance ensures stress transfer between structures 5 and 6 and prevents structures 5 and 6 from being relatively displaced at the interface. it can.

In addition, in FIG. 3, when one or both of the structures 5 and 6 are made of mortar, the same structure as the above-mentioned joining of concrete can be obtained.

FIG. 4 shows a second embodiment of the present invention, which is a joint structure in which one structure 5 is made of concrete and the other structure 7 is made of steel. In this case, the deformed reinforcing bar 4 of FIG. 2 cannot be embedded in the other structure 7 made of a steel material. Therefore, when one of the structures is made of steel, the deformed reinforcing bar 4 of FIG. 2 is cut along the longitudinal axis, and the half-split deformed reinforcing bar 8 is used, and the cut surface 8a is made of steel. The upper half having the knots 8b is made of concrete while being embedded in the structure 5.

The shear resistance due to the joint structure is indicated by the adhesive stress between the nodes 8b and the bearing stress of the node 8b on the one side of the structure 5, and is indicated by the adhesive stress of the cut surface 8a on the other side of the structure 7.

On the other hand, the method of fixing the half-split deformed reinforcing bar 8 to the structure 7 is not limited to adhesion, but may be welding. Further, the other structure 7 is not limited to a steel material, and can be applied to other construction materials as long as the cut surface 8a of the half-split deformed reinforcing bar 8 can be fixed to the end surface to be joined to the one structure 5. it can.

In the present invention, wall slabs and floor slabs can be exemplified as structures, but the scope of application is an RM unit that includes a joint surface between concrete and concrete or mortar, and an opening formed by an existing column and an existing beam. It can be used for joining the joint surface between the opening and the RM unit, the joint surface between the precast plates, and the boundary surface where the concretes expected to be cracked are separated from each other.

1 Floor slab 2 Wall slab 3 Boundary surface 4 Deformed reinforcing bar 4a Rib 4b Section 5 One structure (concrete)
6 The other structure (concrete or mortar)
7 The other structure (steel material)
8 Half-split deformed rebar

Claims (1)

One of the two structures to be joined is made of concrete or mortar, and the other is made of concrete or mortar, and is equally spaced from the ribs provided along the longitudinal axis with the boundary surface of the two structures as the boundary. Reinforcing bars with knots provided in the above two structures were arranged parallel to the interface between the two structures, and shear resistance was given between the two structures by the adhesive stress and bearing stress of the deformed reinforcing bars. A joint structure of a structure characterized by.

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