JP2006233724A - Clip for fixing inward bias inducing joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fitting which is for use in constructing a reinforced concrete building, efficiently fixes an inducing joint to be abutted on a reinforcement, to the reinforcement, has a shape causing no degradation of the strength of skeleton concrete, and is produceable at a low cost. <P>SOLUTION: There is provided a hard steel wire worked so as to have a shape that can firmly and easily fix an inducing joint to the reinforcement, and to exert spring effect. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reinforced concrete building. In such a building, there is a construction method in which a cross-sectional defect is intentionally provided at a predetermined location of the frame concrete. This method is often used especially for civil engineering reinforced concrete buildings. The purpose of this is, for example, when the retaining wall of the retaining wall receives an abnormal external force due to an earthquake or the like, by reducing the strength of the predetermined position of the retaining wall, it induces cracking at this position to absorb the external force, and the entire retaining wall Is to prevent the collapse. The material that provides a cross-sectional defect in the frame concrete is referred to as an induction joint, and there are two types, one that rises toward the mold side with respect to the reinforcing bar and one that rises toward the inside of the frame with respect to the reinforcing bar, In general, most of them are used in combination, but the product of the present invention relates to a hardware for fixing the latter so-called inwardly induced joint.

  The rising height of the introverted induction joint described above is considerably higher than that of the so-called extroverted induction joint that generally rises to the mold side although it depends on the thickness of the housing. Therefore, in the first place, the plate-like induced joints are subjected to strong fluid pressure when placing concrete, but the current method of fixing the induced joints to the reinforcing bars is necessary in any case. The mounting labor and the fixture main body are complicated and complicated shapes. In particular, it cannot be denied that the shape is complicated, which may adversely affect the filling property of the concrete, that is, the strength.

As described above, the fact that the installation is complicated and time-consuming means that the work efficiency is low, and for example, the total cost for installing the induction joint is increased. Therefore, the cost must be reduced by a method that can be installed and installed as quickly as possible.
Moreover, the structure of the part fixed to a reinforcing bar should be simplified, and the joint fixing metal fitting which does not disturb the filling property of concrete cheaply must be provided.

  As a result of diligent research, the present inventor has found that when a plate is placed vertically in contact with a reinforcing bar, it is very easily attached and has a shape that does not have any adverse effect on the filling properties of the concrete to be placed. Was successfully invented.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an image diagram of a hardware according to the present invention. The metal material has a diameter of 2 to 6 mm and is made of hard steel wire. Although this hard steel wire does not reach the spring steel wire in terms of material characteristics, it has extremely high elasticity and exhibits a considerable spring effect even without heat treatment. Here, reference numeral 1 is a portion that sandwiches and fixes the plate-shaped induction joint material, reference numeral 2 is a portion that is slightly longer for the spring effect and stability when the induction joint material is installed on the reinforcing bar, and reference numeral 3 is the It is a part that exerts an effect of hooking on the reinforcing bar and finally fixing the induction joint material in a predetermined position.
FIG. 2 is an image diagram when an introversion-inducing joint material made of an acrylic plate is fixed using a hardware according to the present invention. There are other joint materials such as a thin galvanized steel sheet with a core covered with butyl rubber, which can be fixed in the same manner with the product of the present invention. In this figure, reference numeral 4 is the induction joint material of the acrylic plate, and reference numeral 5 is the reinforcing bar which is in contact with the induction joint material and hooks the portion 3 of the hardware of the present invention.

  When the induction joint material is fixed perpendicularly to the reinforcing bar using the product of the present invention, first, the portion of the above-mentioned reference numeral 1 is sandwiched in the part of the induction joint material corresponding to the position of the reinforcing bar to be fixed in a slightly open state. Then, the induction joint material is fixed in a simple procedure by standing the induction joint material at a predetermined position, pushing the portion of the reference numeral 3 to the opposite side to which the induction joint material of the reinforcing bar is attached, and hooking it on the reinforcing bar. To do. Further, judging from the viewpoint of manufacturing cost, this hardware can be produced by producing a commercially available hard steel wire with only two steps of press, so that the cost can be greatly reduced in terms of both raw material costs and productivity.

Assuming a double-reinforced concrete wall with a wall thickness of 450 mm and a rebar cover of 40 mm, a 2 m high and 1.5 m wide formwork was produced. At this time, the diameter of the reinforcing bar used was a standard product D13, the pitch of the bar reinforcement was 150 mm, and an acrylic plate having a length of 2 m, a width of 100 mm, and a thickness of 6 mm was used as the introversion-inducing joint material. It was arranged on one side in the center of the direction, and this was fixed to five portions of the horizontal stripe almost uniformly with the hardware according to the present invention.
The ready-mixed concrete was placed in the state as described above, and the amount of displacement from the predetermined position of the acrylic plate due to the flow pressure of the ready-mixed concrete was measured. As a result, the maximum was 3 mm on the side in contact with the reinforcing bar, and the maximum was 5 mm on the opposite side, that is, the tip of the acrylic plate. Usually, the allowable range of this displacement is set to 10 mm at the maximum, so that it was confirmed that the induced joint fixing hardware according to the present invention is extremely useful in practice in terms of both the cost due to the workability of installation and the manufacturing cost.

Image of hardware according to the present invention Image diagram when fixing acrylic board using hardware according to the present invention

Explanation of symbols

1. Part that sandwiches the joint material for induction 2. Part that brings the joint material to the rebar side by exerting a spring effect 3. Part that hooks the reinforcing bar 4. Acrylic plate 5. Reinforcing bar

Claims (1)

Prior to placing concrete in the construction of reinforced concrete structures, those that are installed in contact with the rebar in advance, such as hardened steel wires with a characteristic shape that can firmly and efficiently install induced jointing materials, etc. at predetermined locations Hardware consisting of

Images