JPH0826662B2 - Roof slab and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete roof slab and a method for manufacturing the roof slab.

[0002]

2. Description of the Related Art In general, since the concrete is exposed on the lower surface of a roof slab made of concrete, the heat insulating effect is low and the comfort of living tends to be poor. Moreover, since the roof slab has its upper surface in contact with the atmosphere, it is most vulnerable to changes in meteorological conditions, and if cracks occur, rain leakage will occur. As a countermeasure against this, a hard-mix concrete is used so that excess water does not exist at the time of curing, but even in that case, it is difficult to reliably remove excess water, and water droplets remain inside when viewed microscopically. , The whole becomes spongy, the shrinkage coefficient becomes large, and cracks easily occur. In order to remove excess water quickly, it is conceivable to provide a large number of water drain holes in the form, but in that case, the mortar component in the concrete also comes out,
Strength decreases.

[0003]

An object of the present invention is to provide a roof slab having a high heat insulating effect (heat retaining effect).
The invention of (1) aims at promptly removing excess water at the time of hardening to reduce the shrinkage coefficient of the obtained concrete.

[0004]

According to a first aspect of the present invention, a water-permeable layer is fixed to the upper and lower surfaces of a net made of thin wires so that the upper water-permeable layer is fixed to the upper side of a hollow water-permeable plate that leaves a space in the mesh. It is a roof slab with an integral concrete layer.

A second aspect of the present invention is a hollow form water permeable structure in which a water permeable layer is fixed to the upper and lower surfaces of a net made of fine wires on a horizontal formwork having a large number of water drain holes to leave a space in the mesh. It is a method of manufacturing a roof slab in which a concrete is poured so that a board is placed and the upper permeable layer is fixed to the board.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 showing a cross section, reference numeral 1 is a form made of a veneer plate having a large number of water drainage holes 2. When a 10 mm thick veneer plate is used as the mold 1, a drainage hole 2
For example, those having a diameter of 5 mm can be arranged in a grid pattern at a pitch of 100 mm. Of course, they may be arranged in a staggered pattern. A water-permeable plate 3 is placed on the mold 1, and a concrete layer 4 is integrally formed on the water-permeable plate 3 so as to be fixed thereto. The water permeable plate 3 is provided with a net 7 having vertical lines 5 and horizontal lines 6 connected in the center, and water permeable layers 8 and 9 are fixed to the upper and lower surfaces of the net 7 to form a space 10 communicating with the eyes of the net 7. ing. As the vertical lines 5 and the horizontal lines 6, plastic wire rods having a diameter of 2 to 3 mm are used, and these are arranged in a grid pattern with a pitch of 5 to 10 mm and integrated by adhesion to form a net 7. As the water permeable layers 8 and 9, urethane foam having a thickness of 1 to 2 mm and communicating with fine bubbles is used, and this is adhered to the net 7 to form the water permeable plate 3 having a thickness of 5 to 7 mm. The concrete layer 4 is combined with the water permeable plate 3 to form an integral roof slab 11. The mesh 7 may be formed by weaving the vertical lines 5 and the horizontal lines 6 described above.

To make the roof slab 11, the formwork 1 is supported horizontally, the water permeable plate 3 is laid on it, and fresh concrete is poured onto it. Then, as the ready-mixed concrete hardens, the concrete layer 4 is integrated so as to be fixed to the upper permeable layer 8 and the water content therein drops, and then quickly enters the space 10 through the upper permeable layer 8 and continues to the permeable layer 9 and drainage. It goes through the hole 2 and falls downward. In this way, excess water is promptly removed when the concrete hardens.

FIG. 2 is a schematic vertical cross-sectional view of a test apparatus for confirming the water permeation amount of a water-permeable mold, which corresponds to a part of the cross section of a box-shaped container. In the figure, I indicates the case where a general formwork having no holes is used for the formwork 1, and II indicates the drainage hole 2 having a diameter of 5 mm.
A perforated mold having a pitch of 0 mm, III represents a perforated mold having a taper portion having a diameter of 10 mm at the upper end in the upper half, and IV represents the case of the present invention using a water-permeable plate 3. ing. Inject the same amount of raw concrete into each form,
The results of measuring the amount of water permeation, the mortar component, and the transparent water after the elapse of a fixed time (6 hours) were as follows (unit: cc). I II III IV Water permeability 3.5 350.0 200.0 560.0 Mortar component 0.5 195.0 155.0 31.0 Clear water 3.0 155.0 45.0 529.0

As is clear from the above test results, when the mold using the water-permeable plate 3 of the present invention is adopted, the amount of water permeation is higher than that in the case where the mold 1 is simply provided with a large number of drain holes 2. Not only does it increase significantly, but the amount of mortar component permeation decreases.

[0010]

According to the first invention, the concrete layer 4
Since the water permeable plate 3 remains on the lower side, the heat insulation effect (heat retention effect) is increased. In particular, the space 10 inside the water permeable plate 3 enhances the heat insulation performance (heat retention performance), and the concrete layer 4 and the water permeable plate 3
, The weight of the water permeable plate 3 is surely transmitted to the walls and columns (not shown), and the concrete layer 4
The water-permeable plate 3 does not peel off. According to the second invention, since the water-permeable plate 3 also serves as a part of the formwork, surplus water in the concrete layer 4 enters the space 10 from the upper water-permeable layer 8 and passes through the lower water-permeable layer 9 to drain the water. It is discharged downward. As a result, excess water can be promptly removed when the concrete hardens, and at the same time, the concrete layer 4 and the water permeable plate 3 can be integrated so as to adhere to each other, so that the product becomes a solid product and water drops do not remain in the concrete. The shrinkage coefficient is reduced, and the occurrence of cracks can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view when a roof slab is formed by a formwork.

FIG. 2 is a schematic vertical sectional view of a test apparatus.

[Explanation of symbols]

 1 Formwork 2 Drainage Hole 3 Permeable Plate 4 Concrete Layer 7 Net 8 Permeable Layer 9 Permeable Layer 10 Space 11 Roof Slab

Claims (2)

[Claims] 1. A concrete layer is integrally formed so that a water-permeable layer is fixed to the upper and lower surfaces of a net made of fine wires, and a hollow-shaped water-permeable plate that leaves a space in the mesh is fixed to the upper water-permeable layer. The roof slab that was specially installed. 2. A hollow water-permeable plate having a space left in the mesh of a mesh formed by fixing water-permeable layers to the upper and lower surfaces of a net made of fine wires on a horizontal formwork having a large number of water drain holes. , A method of manufacturing a roof slab in which fresh concrete is poured so as to adhere to the upper permeable layer.