JPH0320410Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to the structure of a joint in a cantilever slab for effectively preventing cracks in the cantilever slab.

(Prior Art) Cracks occur in cantilever slabs as the slab concrete expands and contracts, but these cracks have a negative impact on the durability of the building. For this reason, cracks have traditionally been countered by creating joints in the width direction of cantilevered slabs to induce cracks, placing them at regular pitches in the length direction, and applying sealant to these joints. Ta. A method was also adopted in which a wire mesh was laid on the top surface of the cantilevered slab to increase resistance to shrinkage cracks and to disperse the cracks.

(Problem to be solved by the invention) However, the former method requires time and effort to construct, and the latter method has the problem of high construction cost.

The purpose of this invention is to make it possible to effectively prevent cracks in cantilevered slabs economically without requiring much time and effort in construction.

(Means for solving the problem) In this invention, crack prevention plates are embedded in the joints of cantilever slabs in which two-stage reinforcement consisting of upper reinforcement and lower reinforcement are arranged to partition the cantilever slabs. Therefore, the crack prevention plate is intended to suppress the occurrence of cracks. At the joint, the upper reinforcement passes through the crack prevention plate and continues, the lower reinforcement is interrupted, and the ends face each other with the crack prevention plate in between. The crack prevention plate has a length that is approximately equal to the width of the cantilever slab, and has a penetrating portion through which the upper reinforcement serving as the distribution reinforcement passes through in the thickness direction. The penetrating portion may be a hole or groove for holding the upper reinforcement made by punching out the crack prevention plate in the thickness direction, and in the case of a groove, it may be a groove cut vertically from the upper and lower ends. This penetrating portion holds the upper reinforcement in position, and the crack prevention plate may also be used as a spacer when arranging the upper reinforcement. The crack prevention plate is provided with a rainwater permeation prevention plate extending laterally in the width direction at its upper end. The crack prevention plates are arranged at a predetermined pitch in the length direction of the cantilever slab.

(Example) In Figures 1 and 2, the cantilever slab S has two-stage reinforcement consisting of upper reinforcement R and lower reinforcement R1, and crack prevention plates 1 are embedded in the joints. hand,
Partitioning cantilevered slabs. Crack prevention plate 1
is made of a synthetic resin plate with a length approximately equal to the width of the cantilever slab S. The crack prevention plate 1 is provided with a hole 1a for holding the upper reinforcement, which is a penetrating portion through which the upper reinforcement R, which is the force distribution reinforcement, passes. The upper end of the crack prevention plate 1 has a shape that follows the shape of the upper surface of the cantilever slab S, and rainwater penetration prevention plates 1b, 1b are extended from both sides in the thickness direction to this upper end to prevent rainwater penetration on both sides. The board as a whole forms a "H" shape. This rainwater penetration prevention board is suitable for decorative joints on its upper surface.
This prevents rainwater from seeping in from Sa.

Next, construction will be explained.

The crack prevention plate 1 is set on the assembled slab formwork in the width direction of the cantilevered slab, and in the same way, multiple crack prevention plates are arranged at a pitch of 2.5 to 3.0 meters, and then the main reinforcement Ra, upper reinforcement R, and lower reinforcement The reinforcements R are arranged, and the upper reinforcements are held in position by passing them through the holes 1a, ... of each crack prevention plate 1, then concrete is poured, and finally the rainwater penetration prevention plate 1b is placed.
Form a decorative joint Sa on top.

When interrupting concrete pouring work, the crack prevention plate 1 may be used as a weir plate.

FIG. 3 shows another embodiment. In this example, the height of the crack prevention plate 11 is equal to the thickness of the cantilever slab S, and the rainwater penetration prevention plate 11b at the upper end,
11b is buried within the cantilevered slab. 11
A is a hole for holding the upper muscle through which the upper muscle R passes.

The rainwater permeation prevention plates 11b, 11b have their tip portions bent upward, and the entire plate is formed into a groove shape. By bending the tip in this way, water that permeates from the top surface of the cantilever slab will be transmitted to this rainwater infiltration prevention plate and flow to the drainage ditch side of the cantilever slab, thereby preventing water leakage to the bottom surface of the cantilever slab. Can be effectively prevented.

(Effects of the invention) As explained above, according to this invention, the crack prevention plate divides the slab concrete into a border state while ensuring the continuity of the cantilevered slab by making it possible for the upper reinforcement, which is the distribution reinforcement, to pass through. Because you can
Cracks can be effectively prevented. Since there is no need for conventional wire mesh and there is no need to create trigger joints, construction is time-consuming and economically advantageous.In addition, rainwater penetration prevention plates can be installed laterally from the top edge of the crack prevention plate. Since the rainwater infiltration prevention plate is integrated with the crack prevention plate, the workability is further improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the state of use, with the main reinforcing bars omitted, FIG. 2 is an enlarged sectional view, and FIG. 3 is a large sectional view showing another embodiment. 1, 11...Crack prevention plate, 1a, 11a...Penetration part (hole for holding upper reinforcement), 1b, 11b...Rainwater penetration prevention plate, R...Upper reinforcement, R1...Lower reinforcement, S...Cantilever slab.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Crack prevention plates are buried in the joints of a cantilever slab in which two-stage reinforcement consisting of upper reinforcement and lower reinforcement is arranged, and the above-mentioned upper reinforcement is the distribution reinforcement. penetrates the crack prevention plate, the lower reinforcement is cut by the crack prevention plate, and the ends thereof face each other with the crack prevention plate in between, and the crack prevention plate has a length approximately equal to the width of the cantilever slab. It has a penetration part through which the upper reinforcement passes through, and a rainwater penetration prevention plate extends laterally in the width direction at the upper end, and the penetration part is a hole or groove for retaining the upper reinforcement. Structure of joints in cantilevered slabs. 2. Claim 1 of the Utility Model Registration Claims: The structure of a joint in a cantilevered slab, wherein the rainwater permeation prevention plate has an upwardly bent tip.