JP4958081B2 - Con stop sponge - Google Patents

Description

The present invention relates to a member for a joint surface of concrete of a reinforced concrete structure. In a reinforced concrete building, it is impossible to avoid the occurrence of a jointed surface of concrete due to the work process, and this extends to all the structures such as beams, columns and floors. Of particular concern is the case of beams and floors where it is necessary to stop the ready-mixed concrete on a vertical surface other than the formwork veneer plate. The contact pressure is also high and extremely troublesome. The present invention relates to a raw control member for this beam.

  Conventionally, there are a so-called air fence or a so-called air fence that has a large drop and a lath net installed on the joint surface. Of these, the latter cannot be used in buildings using high-strength concrete of 60N (Newton) or higher, whose demand has increased in recent years, because the fluidity of the concrete is extremely high. Therefore, the former air fence is used exclusively. This is a construction method in which a tube inflated with compressed air is installed on the joint surface without any gaps, and the contractor is undertaking this construction exclusively by so-called material construction.

  In the above-described air fence, since the distal end portion of the tube is hard, the flexibility is low, and the gap at the bottom that is the most important for stoppering is unavoidable. In addition, since it has a structure that exhibits the function of stopping the connection only after air is injected into the tube, it is difficult to orderly install it. Furthermore, the contract price is high due to the exclusive construction by a single contractor.

As a result of diligent research, the present inventor has succeeded in producing a jig that has a very low manufacturing cost by using a commercially available sponge as a main material, and that has a very high leakage prevention performance of raw concrete on a concrete joining surface.
The product of the present invention is reinforced by placing a reinforcing bar on the sponge core formed in a prismatic shape, and is covered with a double plastic bag for the purpose of improving workability when installing and dismantling the product of the present invention. It is characterized by that. This is arranged in a line on the joint surface without any gaps, and a back-up jig fixed using the stirrup bars of the frame beam bars counteracts the surface pressure of the raw concrete and prevents leakage.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an image diagram of a single stopper jig according to the present invention. Here, reference numeral 1 is a sponge formed in a prismatic shape, and reference numeral 2 is a reinforcing bar for reinforcing it, which is inserted into the core of the sponge and fixed with an adhesive. When actually used, this is covered with a double plastic bag to reduce the frictional resistance when it is inserted and installed, and when it is pulled out and dismantled. FIG. 2 is a cross-sectional view thereof. Reference numeral 3 denotes an inner plastic bag, and reference numeral 4 denotes an outer plastic bag.
In this way, one of the purposes of using a plastic bag is to install the product of the present invention between stirrups of stirrups, so if the pitch is small, pump the air in the plastic bag. This is because it is necessary to reduce the cross-sectional area of the sponge by the atmospheric pressure to make it thinner and to make it easier to install. In this case, after the installation is completed, the suction port of the plastic bag is opened to restore the original elasticity of the sponge, and the adjacent sponges are brought into close contact by the expansion force.

FIG. 3 is also an image diagram of the jig according to the present invention, and is a backup member for maintaining the shape of the above-mentioned prismatic sponge against the surface pressure of the raw concrete on the joining surface.
Here, reference numeral 5 denotes a main body portion of the product of the present invention, and two are used as a set as shown in the figure. Reference numeral 6 is a lasting sign that is provided when the reference numeral 5 is installed in the formwork. Reference numeral 7 denotes a hook portion for fixing the reference numeral 5 to the stirrup or width stop bar of the beam line, and reference numeral 8 denotes a reinforcing bar for preventing harami (a swelling of the stopper material due to the surface pressure of the raw concrete). It fits on a steel wire that has been processed into a letter shape and welded to 5. This harassment prevention reinforcing bar is cut slightly shorter than the beam width, facilitating dismantling and removal after setting concrete. FIG. 4 is a cross-sectional view when the prismatic sponge and the backup jig according to the present invention are installed at the joint portion of the beam bar. Here, reference numeral 10 is a main bar of the beam, reference numeral 11 is also a stirrup, and reference numeral 12 is a bottom plate of the formwork.

As described above, all the jigs according to the present invention are manufactured by simple processing of a relatively inexpensive commercial material, so that the manufacturing cost is extremely low. Compared to the air fence method, it can be offered about 20% cheaper.
In addition, when the product of the present invention is constructed, the outer poly (vinyl chloride) bag described above is used when the main body is made of sponge and is forcibly compressed before being inserted into the formwork to form a square shape into a plate shape. It is also possible to temporarily prevent the sponge from expanding by welding the opening. As a result, the sponge can be placed on the mold without resistance, and the sponge is restored to its original shape by cutting and aerating the welded portion at the final stage of construction. The expansion force at this time causes the sponge and the beam to be in close contact with each other, and against the lateral pressure of the raw concrete, preventing leakage of the raw concrete from the joining surface.

Assuming a beam with a beam width of 500 mm and a beam formation of 850 mm, a formwork with a length of 800 mm was made. In this, four D35 rebars were arranged at 120 mm pitch as the upper and lower bars, for a total of eight. Were bound and fixed with five stirrups with a pitch of 200 mm using D13 rebars. The side and bottom cover is 50 mm.
In the above-described state, the stopper test using the product of the present invention in which the center portion of the mold was the raw joint joint surface was performed. The cross-sectional dimension of the sponge used in this test was 75 × 100 mm and the length was 1200 mm. The D13 rebar was inserted into the center of the sponge as a reinforcing core, and fixed by adhesion. Furthermore, this square columnar sponge was covered twice with a 0.8 mm thick plastic bag, and eight of these were lined up to make a stopper.
On the other hand, regarding the backup jig installed on the opposite side of the cast-in-place with the columnar sponge row as the boundary, the D16 rebar is attached to the main body portion of the above-mentioned reference numeral 5, and the D16 rebar is also used as a harassment prevention material of the reference numeral 8. used.
The ready-mixed concrete placed in this test was blended with a composition of 60 N, and the flow test value was 520 mm. The ready-mixed concrete was placed up to the top of the formwork, and the presence or absence of leakage and the state of harami were verified.
As a result, there was no leakage of raw concrete, and the harami was 35 mm even at the largest part, confirming that there was no problem in practical use.

  The image figure of the stopper fixture simple substance by this invention.   Sectional drawing of this invention goods.   The image figure of the backup member by this invention.   Sectional drawing of this invention product installed in the joint surface.

Explanation of symbols

1. Sponge molded in a prismatic shape 2. Reinforcing bar 3. Reinforced plastic bag 4. Outer poly bag 5. Back-up jig main body 6. Nigiri part 7. Hook part 8. Harami prevention. Reinforcing bar 9, Reinforcing bar receiving part 10, Beam main bar 11, Beam stirrup 12, Form plate bottom plate

Claims (1)

This is a so-called coning-stopping member on the joint surface when joining the concrete of the beam, and it has a remarkable effect in preventing the leakage of the raw concrete in the joint part formed into a prismatic shape so as to obtain a wide concealing area per piece. The core of the sponge with a reinforcing bar is reinforced with a reinforcing bar, and its outer periphery is covered with a double plastic bag for the purpose of increasing workability when installing in the stopper and removing after solidifying the concrete A jig that can be used repeatedly.

Images