JPH0960121A - Method for joining steel shell and reinforced concrete members - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] At a joint between a reinforced concrete structure (RC) and a steel shell structure, a reinforcing rod 5 is extended from the side of the reinforced concrete portion 4 into the inside of the steel shell 1 of the joint 2 and concrete 6 is struck. In the joining method to be installed, the reinforced concrete part 4
The reinforcing bar 5 and the steel shell 1 extending from the side to the joint are indirectly coupled to each other to improve the deformation performance and obtain a highly reliable joint structure. SOLUTION: By arranging a permanent material 7 having a certain expansibility as an expansive material in a concrete 6 to be placed in a joint 2 between a steel shell 1 and a reinforced concrete part 4, the expansive material is expanded. A lateral restraining pressure is applied to the concrete 6 by the force to indirectly connect the reinforcing bar 5 extending from the reinforced concrete portion 4 side and the steel shell 1.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for joining a steel shell and a reinforced concrete member.

[0002]

2. Description of the Related Art Reinforced concrete structures (RC) and prestressed concrete structures (PC) are advantageous in terms of economy and durability in columns and beams in buildings, bridges and bridge piers as structures, while The steel shell structure is considered to be advantageous in terms of weight reduction and rapid construction, but in recent years, composite structures and mixed structures that make the most of both characteristics have been realized.

In the composite structure or mixed structure of the reinforced concrete structure (RC) or the prestressed concrete structure (PC) and the steel shell structure, the reinforced concrete structure (RC) or the prestressed concrete structure (P
A problem is that the strength of the joint between C) and the steel shell decreases.

Conventionally, as a method for ensuring the strength of the joint portion, for example, as shown in FIG. 7, ribs are provided so as to project inside the joint portion 2 of the steel shell 1, or the dowels 3 are attached so as to protrude. On the other hand, a reinforcing bar 5 is extended from the reinforced concrete part 4 into the inside of the joint part 2, concrete 6 is placed inside the joint part 2, and stress is transmitted from the steel shell 1 to the reinforced concrete part 4 through the concrete 6. There is a way to do it.

In addition to the above structure, a tension member made of PC steel material such as PC steel wire or PC steel rod is stretched inside the joint portion 2, and the steel shell 1 and the reinforced concrete portion 4 are made of this tension material.
There is also a way to connect with.

[0006]

In the joint structure in which the concrete 6 is simply placed inside the steel shell 1 of the joint 2, there is a problem in the filling property of the placed concrete 6 (around the concrete) or there is a breathing water. There is a possibility that the joint structure may lack reliability due to the influence of the gap caused by the occurrence of cracks or the shrinkage of concrete, and in many cases, the tenacity (toughness) becomes insufficient.

[0007] On the other hand, the method of tightening the PC steel material with the tension material solves some of the inconveniences described above, but the structure is complicated and economically insufficient.

It is an object of the present invention to provide a joining method for joining a steel shell and a reinforced concrete member which eliminates the disadvantages of the conventional example, improves the deformation performance, and obtains a highly reliable joining structure.

[0009]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention extends a reinforcing bar from the side of a reinforced concrete structure to the inside of a joint steel shell at the joint between a reinforced concrete structure and a steel shell structure, and at the same time hits concrete. In the joining method to be installed, an injection hole forming member is placed in advance in the joint concrete to be placed inside the steel shell of the joint, and an expansive material is injected into the injection hole of the injection hole forming member, and the expansion is performed. The gist of the present invention is to apply a lateral restraining pressure to the concrete at the joint portion by the material, and indirectly connect the reinforcing bar extended from the reinforced concrete structure side to the steel shell by this lateral restraining pressure.

According to the present invention, the deformability is improved by indirectly connecting the reinforcing bar and the steel shell extending from the reinforced concrete portion side to the joint with the lateral restraining pressure applied to the joint concrete by the expansive material.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional front view of a joint portion (SRC joint) between a reinforced concrete structure and a steel shell structure showing a first embodiment by a joint construction method of a steel shell and a reinforced concrete member of the present invention, and FIG. 2 is A-A in FIG. It is a line sectional view.

The basic structure of the joint is similar to that of the conventional example shown in FIG. 7, in which ribs and dowels 3 are mounted inside the joint 2 of the steel shell 1, while the reinforced concrete part 4 to the rebar 5 are connected to the joint 2. It extends between the inner gibber 3.

Then, before the concrete 6 is placed inside the joint 2 of the steel shell 1, a sheath as an injection hole forming member.
After arranging 11 and pouring the concrete 6, the permanent material 7 having a certain expansiveness is injected as an expansive material into the inside of the hole formed by the sheath 11.

The sheath 11 may be a pipe, a tube or the like, and various materials such as paper, synthetic resin or metal may be considered, but a flexible material may be used, and as an example, the steel shell 1 as shown in FIG.
They were arranged in a cross shape in the cross-sectional direction so that the arrangement intersects at the central portion of the joint portion 2.

As the permanent material 7 having a certain expansive property, for example, lime used as a static crushing material for concrete structures, cement mixture, expandable synthetic resin, expansive rubber or other expansive compound. Alternatively, a mixture of these with cement or aggregate is used.

As described above, the concrete 6 is cast inside the joint 2 of the steel shell 1 and the permanent material 7 having a certain expansiveness is placed in the sheath 11 or in the hole after the sheath 11 is removed. When arranged, an expansive force acts from this permanent material 7 in the direction indicated by the arrow in FIG. 2, and a high lateral restraining stress is introduced into the concrete 6.

As a result, the reinforcing bar 5 extending from the reinforced concrete part 4 into the joint part 2 and the steel shell 1 are indirectly bonded, and the deformation performance is improved.

It is generally known that the strength of concrete in the axial direction is improved by increasing the number of reinforcing bars of the concrete member and increasing the restraining force in the lateral direction. As shown in FIG. 6, the concrete member in the axially compressed state has a strength which is several times as high as the uniaxial compressive strength and a deformation characteristic which is 10 times or more,
In the present invention, the high lateral restraint stress introduced into the concrete 6 of the joint 2 also has the same strength and deformation characteristics as those given to the concrete member in the triaxially compressed state.

FIG. 3 shows a second embodiment of the present invention and is a partially cutaway front view of a bridge pier that does not require an anchor frame. FIGS. 4 and 5 are horizontal plan views of the same as above, showing a reinforced concrete (RC) foundation. Steel shell 1 at the part that becomes part 8 and pier 9
This is to be performed on the joint portion 2 with.

After the foundation 8 is constructed, the steel shell 1 which becomes the bridge pier 9 is built in, the anchoring rebar 13 for anchoring from the foundation 8 is extended into the joint 2 at the bottom of the steel shell 1, and the cross beam 10 is also used. The anchor rebar 12 from the above is extended to the upper joint part 2 and the sheath 11 for injecting the permanent material 7 having a certain expansive property is attached to the steel shell 1.
Placed inside.

After that, concrete 6 is poured into the steel shell 1, and after hardening, the permanent material 7 having a certain expansiveness is injected into the sheath 11 to make the concrete 6 restrained by the steel shell 1. A lateral restraining stress due to the expansion force of the permanent material 7 is introduced.

FIG. 4 shows a case in which the pier 9 is a cylinder, and a sheath 11 and a permanent material 7 having a certain expansivity to be injected into the sheath 11.
Are arranged along the inner peripheral surface of the steel shell 1. When the bridge pier 9 is a prism as shown in FIG. 5, a cross-shaped arrangement is performed such that the arrays intersect at the center.

As a result, anchor anchor rebars 13 and anchor rebars extending from the base 8 which is the reinforced concrete part 4 and the transverse beam 10 into the joint 2 with the steel shell 1 which is the pier 9
12 and the steel shell 1 are indirectly bonded to each other, so that the deformation performance is improved.

In the above embodiment, the sheath 11
Was left in the concrete 6 as it was, and a permanent material 7 having a certain expansiveness was injected thereinto. However, as another embodiment, after hardening the concrete 6, the sheath 11 is removed to leave only a hole, and Permanent material 7 may be injected.

[0025]

As described above, according to the method of joining the steel shell and the reinforced concrete member of the present invention, concrete is placed in the joint portion of the steel shell, and the stress is transmitted from the steel shell to the reinforced concrete portion through this concrete. In the joining method to
By arranging the expansive material in the joint concrete, the expansive force of this expansive material indirectly connects the reinforcing bar and the steel shell extending from the side of the reinforced concrete part to the joint,
The deformation performance is improved and a highly reliable joint structure can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an SRC joint showing a first embodiment in which a method for joining a steel shell and a reinforced concrete member according to the present invention is carried out.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing a first embodiment in which the joining method of the steel shell and the reinforced concrete member of the present invention is carried out.

FIG. 3 is a partially cutaway front view of a pier showing a second embodiment in which the method for joining a steel shell and a reinforced concrete member of the present invention is carried out.

FIG. 4 is a cross-sectional plan view of a pier showing a second embodiment in which the method for joining a steel shell and a reinforced concrete member of the present invention is carried out.

FIG. 5 is a cross-sectional plan view of another example of the pier showing the second embodiment in which the method for joining the steel shell and the reinforced concrete member of the present invention is carried out.

FIG. 6 is a characteristic curve diagram showing a stress level due to a high lateral restraint member.

FIG. 7 is a vertical sectional front view showing a conventional method for joining a steel shell and a reinforced concrete member.

[Explanation of symbols]

1 ... Steel shell 2 ... Joint part 3 ... Givel 4 ... Reinforced concrete part 5 ... Reinforcing bar 6 ... Concrete 7 ... Permanent material with constant expansivity 8 ... Foundation part 9 ... Bridge pier 10 ... Horizontal beam 11 ... Sheath 12 ... Anchor rebar 13 ... Anchor rebar for anchoring

Claims (1)

[Claims] 1. In a joining method between a reinforced concrete structure and a steel shell structure, in which a reinforcing rod is extended from the reinforced concrete structure side into the inside of the joining steel shell and concrete is placed, the inside of the joining steel shell is driven. An injection hole forming member is previously arranged in the joint concrete to be installed, and an expansion material is injected into the injection hole in the injection hole forming member, and the expansion material applies a lateral restraining pressure to the joint concrete. A method for joining a steel shell and a reinforced concrete member, characterized by indirectly connecting a steel bar and a reinforcing bar extending from the side of a reinforced concrete structure by lateral restraining pressure.