JPH0414233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for placing a concrete slab.

[Problem that the invention seeks to solve]

Conventionally, when pouring a concrete slab, a formwork such as plywood was placed on the underside of the slab and concrete was poured into the slab. In this method, a complicated formwork is required to form an uneven surface such as a joystick slab on the lower surface of the slab, which significantly increases the time and effort of the formwork carpenter. There is also a method of forming an uneven surface using a void method in which a tube filled with fluid is inserted, but this method has the disadvantage of being difficult to handle due to buoyancy.

This invention was made in view of the above circumstances. The purpose is to reduce the labor of formwork carpenters and to propose a method for efficiently pouring concrete slabs with uneven lower surfaces, such as joist slabs.

[Means for solving problems]

This method of placing a concrete slab involves placing a pine-like membrane form on a support frame, which forms an uneven surface of a predetermined shape by sealing fluid such as air or water on the lower surface of the concrete slab to be placed. The method is characterized in that the mold is placed in a mold, and a fluid is sealed in the mold to form an uneven surface, and then concrete is poured on top of the mold, and after hardening, the fluid in the mold is discharged and the mold is removed.

This casting method will be explained below with reference to illustrated embodiments.

In FIG. 1, when placing a concrete slab, a support frame 1 is placed below the slab. The support frame 1 is composed of a scaffold frame 2 and a pipe 3 disposed on the upper surface of the scaffold frame 2, as shown in FIG. 8a, and forms a horizontal support surface of a desired height.

As shown in FIGS. 2 and 8b, a pine-like membrane formwork 4 (hereinafter referred to as formwork) is placed on the upper surface of the support frame 1,
At the required position, it is fastened to the support frame 1 (not shown). As shown in Fig. 9, the formwork 4 is made up of two upper and lower air-impermeable membrane materials 5 and 5' stacked on top of each other, the periphery of which is airtightly fixed, and the upper membrane material 5 is provided with a bulge of a desired shape. . When air, water, etc. are injected between the membrane materials 5 and 5', the bulge portion of this formwork 4 swells to form a rectangular convex portion 6, and the portion other than the convex portion is the membrane material 5, Plane portions 7 with narrow intervals 5' are formed.

Figure 3 shows a state in which air is sealed in a mold 4 placed on a support frame 1, and convex portions 6 such as rectangular parallelepipeds, pyramids, cones, hemispheres, etc. are formed on the top surface in a vertical and horizontal lattice pattern or in a horizontal lattice pattern. It stands out. In this state, as shown in FIG. 4, reinforcing bars 8 are arranged in the vertical and horizontal directions between the convex portions 6, 6. Concrete 9 is then poured onto this formwork 4 (Fig. 5). After concrete 9 has hardened,
The air in the formwork 4 is removed and contracted (Fig. 6), the support frame 1 is dismantled and removed, and the formwork 4 is demolded, completing the casting of a concrete slab 10 with the desired uneven surface on the lower surface. (Figure 7).

The pine-shaped membrane form used in this casting method uses a highly air-impermeable membrane material whose main material is vinyl chloride resin, polyester resin, rubber, or the like. In order to improve pressure resistance, shape retention, strength, etc., reinforcing fibers or fabrics may be embedded or laminated. In order to maintain the formwork in the desired shape when filling fluids such as air or water, the upper and lower membrane materials may be connected with strings for adjusting the distance as necessary, or in order to form a flat surface. A highly rigid plate may be attached to the membrane material at a desired location.

The surface of the formwork is coated with a resin with good mold release properties such as Teflon resin, or a lubricant, etc.
Alternatively, a thin film with good mold releasability such as polyethylene film is layered before concrete is poured to make demolding easier, prevent damage to the formwork, prevent dirt, etc., and promote repeated use of the formwork. can be achieved.

Further, this driving method can also be used in combination with the unbonding method, for example, by using reinforcing bars that have been subjected to an unbonding process in the reinforcing bar arrangement shown in FIG.

〔Effect of the invention〕

The present invention is as described above, and it is possible to cast a concrete slab with an uneven lower surface such as a joint slab without using complicated formwork such as plywood.
This has the effect of reducing the labor of formwork carpenters and increasing construction efficiency.

[Brief explanation of drawings]

Figures 1, 2, 3, 4, 5, 6, and 7 are longitudinal cross-sectional views showing the concrete slab casting process in the example, and Figures 8 a and b are perspective views of the support frame and the pine-like membrane formwork. , FIGS. 9a and 9b are a longitudinal sectional view and a plan view of a pine-like membrane formwork containing a fluid. 1...Support frame, 2...Scaffolding frame, 3...Pipe,
4...pine-shaped membrane formwork, 5,5'...membrane material, 6...
...Convex portion, 7...Flat portion, 8...Reinforcement, 9...Concrete, 10...Slab concrete.

Claims (1)

[Claims] 1. A pine-shaped model frame that forms an uneven surface of a predetermined shape by filling fluid is placed on the support frame at the lower surface of the concrete slab to be poured, and the fluid is sealed in the mold. 1. A method for placing a concrete slab, which comprises: forming an uneven surface, placing concrete thereon; and, after hardening, draining fluid in the formwork and removing the form.