JPH0122024Y2 - - Google Patents

Description

[Detailed explanation of the invention] "Industrial application field" This invention improves the structure of the PCaF version joint part of a reinforced concrete (RC) shear wall using precast reinforced concrete external wall semi-finished products (hereinafter referred to as PCaF version). related to.

“Conventional technology” In recent years, PCaF has been used on the exterior walls of reinforced concrete buildings.
Example of construction using plates (hereinafter collectively referred to as PCaF wall)
is rapidly increasing. Here, PCaF wall is made by using a precast board with external wall finish as the outer formwork, and pouring cast-in-place concrete inside it.
The exterior wall is a combination of precast boards and post-cast concrete walls, and the advantages of this construction method are: 1. Improved quality of exterior wall finish (preventing tiles from falling off, etc.) 2. Streamlining exterior work and improving safety in dense urban areas. However, in structural design when using PCaF walls as earthquake-resistant walls, the PCaF plate is not considered as a structural element, and the wall thickness required for earthquake-resistant design is secured by post-cast concrete, so wall reinforcement is not considered. state of
It has come to be considered that PCaF plates are used as structural elements by combining PCaF plates and reinforced concrete produced on-site to construct sturdy structures. In most cases, a PCaF plate joint is installed on the structural wall surface.

That is, as shown in FIG. 2, the joint part of the conventional PCaF plate has a cross-sectional defect part b within a range a that is considered to be a structure. Therefore, reinforcing bars or plates c that match the concrete strength of the defective part b
This is done in two ways: either by considering the strength in terms of strength, or by considering only the cross-section of concrete produced on-site.

In the figure, d and d are PCaF version, e is PCaF version joint part, f is on-site manufactured reinforced concrete, and g is
The wall reinforcement level of PCaF version d is shown.

``Problem that the invention aims to solve'' However, in the shape of the PCaF plate d that is currently normally installed, even after it is integrated with the reinforced concrete produced on site f, the shear rigidity of the joint part e is lower than that of other parts. It is considered an inferior part.
In particular, it appears characteristically in the initial shear stiffness, which is thought to be controlled by the concrete cross section. As a result, more materials than necessary, an increase in design load, and a decrease in work efficiency are unavoidable.

By the way, according to the results of a comparative test, the one shown in Figure 2 has a secant stiffness of about 90 at the point where noticeable cracks occur at the joint compared to the one with integrally cast walls.
%, and the maximum yield strength is approximately 90%.

"Means to solve the problem" In view of the above-mentioned circumstances, this project improves the joint part of the conventional PCaF plate, contributing to increased shear rigidity, increasing work efficiency, reducing costs, and ensuring quality. The gist of this is that the inner periphery of the PCaF plate with wall reinforcements is chamfered at an appropriate angle in advance at the factory, and the on-site produced concrete is poured to that level.
The aim is to ensure the same concrete cross section as the other parts at the plate joint, and to place splinter bars in the field-produced concrete inside the PCaF plate to compensate for the insufficient amount of reinforcing bars at the joint.

"Effect", "Example" This will be explained in detail below based on the drawings.

Figures 1a and b show a cross-sectional view and an elevation view of the proposed joint part, respectively. In the figure, 1 shows the state in which wall reinforcements 3 are arranged, with the inner periphery being chamfered at an appropriate angle 2 in advance at the factory.
This is a PCaF plate, and this is erected while incorporating concrete stopper 4, and in this state, this PCaF plate 1
Install reinforcing bars 5 on the inside corresponding to the amount of reinforcing bars that are insufficient at each PCaF plate joint part, and then assemble the wall reinforcements 7 in the on-site produced concrete 6, erect the inner formwork (not shown), and then pour concrete 6. will be carried out.

With an improved configuration that ensures the same concrete cross section as other parts in the joint part mentioned above,
It has been confirmed that it is possible to widen the cross-sectional dimension of the conventional joint and secure a larger concrete cross-sectional dimension without increasing the amount of reinforcing steel, concrete, etc.

In other words, the results of a comparative test with an integral cast wall similar to the one described above show that the secant stiffness at the point where significant cracking occurred at the joint was about 95%, and the maximum yield strength was about 95%.
It was 98%.

"Effects of the Invention" As a result of the performance improvement achieved by the configuration of the present invention as described above, the present invention can achieve various effects as listed below.

The conventional reinforcing material for the defective section is no longer required, increasing work efficiency and reducing costs.

The cross section (concrete) of the PCaF plate can be used effectively, reducing the weight of the frame.

It is possible to simply secure the concrete cross section without using the conventional method of replacing the defective concrete cross section with reinforcing bars, etc., making it clear in terms of structural methods.

[Brief explanation of the drawing]

1A and 1B are a cross-sectional view and an elevational view of the joint portion of the present invention, and FIG. 2 is a cross-sectional view of a conventional joint portion. Explanation of symbols, a... Range considered as a structure, b...
...Cross section defect, c...Reinforcing bar, d...PCaF version, e
... PCaF version joint part, f ... Field-produced reinforced concrete, g ... Wall reinforcement level, 1 ...
PCaF version, 2... Chamfer, 3... Wall reinforcement, 4... Concrete stopper, 5... Splinter reinforcement, 6... On-site produced concrete, 7... Wall reinforcement.

Claims (1)

[Scope of utility model registration request] Assuming that the inner periphery of a pre-cast reinforced concrete external wall semi-finished product with wall reinforcements arranged is chamfered at an appropriate angle in advance at the factory and concrete produced on-site is poured to that level, even at the joint part of the external wall semi-processed product. An external wall made of precast reinforced concrete, characterized by ensuring a concrete cross section equal to that of other parts, and providing splint reinforcements corresponding to the insufficient amount of reinforcing bars at the joints in the on-site produced concrete inside the semi-finished external wall. Structure of the joint part of a reinforced concrete shear wall using a semi-finished product.