JPH0447068A - Permeable canvas stretching simple form - Google Patents

Abstract

PURPOSE:To lower the side pressure of concrete by stretching permeable canvas made of synthetic fibers on the single surface or both of the front and back surfaces of a net shaped body which is formed in such a way that reinforcing bars are intersected crosswise. CONSTITUTION:Reinforcing bars 1 are intersected crosswise while each intersection 2 of them is welded together, so that a net shaped body 3 is thereby formed, and permeable canvas 4 made of synthetic fibers in then stretched on the front and back surfaces of the net shaped body 3. The woof of the canvas 4 made of synthetic fibers is made up out of roughly 50 to 150 pieces of monofilament which is roughly 65 to 75 denier, so that plain weave fabric is thereby formed. In the second place, excess water 6 contained in concrete 5 placed is drained through the canvas 4 made of synthetic fibers, so that the side pressure P of concrete 5 is lowered to a great extent. This constitution, can thereby enhance the accuracy of a skeleton.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a simple water-permeable fabric-covered formwork used for constructing concrete structures, etc.

[Conventional technology]

Traditionally, formwork for constructing concrete structures can be roughly divided into wooden formwork using plywood, etc. for the sheathing, and steel formwork using steel plates for the sheathing.In addition, synthetic fiber cloth, Water-permeable formwork made by pasting plastic film on foamed plastic, or plastic film with holes on synthetic fiber nonwoven fabric, attached to plywood with through holes. It has been known.

[Problem to be solved by the invention]

Conventional wooden formwork not only requires careful assembly and disassembly work to be used repeatedly, but also has a poor finish on the concrete surface after 2 or 3 uses, and steel formwork is extremely heavy to handle. It is not easy to use, and requires a lot of effort and maintenance such as cleaning and anti-corrosion treatment after use.Furthermore, water-permeable formwork quickly removes excess water from the concrete, speeding up the hardening of the concrete and allowing for early demolition. In addition to making molding possible, it also reduces damage to wooden sheathing boards due to moisture in the concrete.By making the concrete surface denser, it prevents corrosion of reinforcing bars due to rainwater infiltration after hardening, and also reduces the damage to wooden sheathing boards caused by moisture in the concrete. The purpose is to make the concrete beautiful, and the lateral pressure generated by the weight of the poured concrete is supported by the plywood, so the concrete generated on the sheet material that replaces the weir board in the lightweight and simple structure formwork described later. It does not have the technical idea of reducing the lateral pressure of the mold, and a formwork worker is required to assemble the formwork, and the recent shortage of skilled workers has led to an increase in construction costs, so precision is not strictly required. For partial concrete structures, there has been a demand for the development of lightweight and simple-structured formwork that does not require formwork. The object of the present invention is to provide a simple formwork that can reduce the lateral pressure of concrete and can be applied to parts that require precision.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has a mesh structure formed by intersecting reinforcing bars vertically and horizontally.
-50 to 150 monofilaments of ~55 denier are used as weft yarn, and 50 monofilaments of 65 to 75 denier
A plain fabric made of synthetic fibers woven with ~180 warp yarns is attached, or a simple formwork for covering water-permeable fabric is taken.

[For production]

The applicant for this patent previously applied for a simple formwork in which plastic sheets were pasted on the front and back sides of a reticulated steel body
This simple formwork was filed as No. 273501, but as shown in Fig. 4, when the concrete 5 is placed, the lateral pressure P due to the concrete 5's own weight is applied to the plastic sheet 4.
This invention solves the problem that the concrete structure cannot be constructed in the designed shape because it swells outward from between the meshes of the reinforcing bars 1a that extend over the meshes of the reinforcing bars 1a that form the net-like structure. As shown in FIG. 3, a water-permeable synthetic fiber cloth 4 is used instead of the plastic sheet.
Since surplus water 6 in the poured concrete 5 is drained through the synthetic fiber cloth 4, the lateral pressure P of the concrete 5 is significantly reduced.
Since it is a woven fabric, it has a higher tear strength than a film-like sheet, and this combined with the fact that the blistering of the synthetic fiber cloth 4 is kept to a minimum, thereby significantly improving the precision of the frame of the concrete structure.

〔Example〕

An embodiment of the invention will be described with reference to the drawings.

In FIGS. 1 and 2, reinforcing bars or steel bars (referred to as reinforcing bars in this specification) 1 are crossed vertically and horizontally, and the intersection points 2 are welded to form a rod-like body 3. The outer diameter of the reinforcing bars 1 is approximately 3 to 12 m5, and the vertical and horizontal intervals between the reinforcing bars 1 are 2
They are approximately 5 to 200 mm in length and arranged in a perpendicular grid pattern.

Water-permeable synthetic fiber cloth 4 is bonded to the front and back sides of the net-like body 3 by welding, gluing, stapling, etc. so as to sandwich the reinforcing bars 1 from both sides. In this case, if the adhesion between the reinforcing bars 1 and the synthetic fiber cloth 4 is strong, the synthetic fiber cloth 4 may be bonded only from one side of the net-like body 3 or at the intersection 2 of the rope-like body 3. Alternatively, the adhesive may be adhered by applying a patch cloth from the back side.

As the synthetic fiber cloth 4, fibers such as polyester, nylon, or polypropylene are used, and the weft is a monofilament of 45 to 55 deniers.
A plain weave of 25 to 180 monofilaments of 65 to 75 deniers is used as the warp yarn.

In this case, 50 to 150 untwisted 45 to 55 denier monofilaments are used as the weft, and 50 to 180 untwisted 65 to 75 denier monofilaments are used as the warp.
Although plain weave has good water permeability, it does not allow cement particles to flow out, making the concrete surface dense and providing sufficient strength.

〔Effect of the invention〕

In this invention, the framework is a mesh of reinforcing bars, and the parts corresponding to the weir plates are made of water-permeable synthetic fiber cloth, so it is extremely lightweight and easy to handle. The formwork can be assembled quickly, and the concrete surface has a good finish, especially since excess water from poured concrete is drained through the water-permeable synthetic fiber fabric, making it easier to assemble the concrete than the water-permeable synthetic fabric fabric. Since the lateral pressure caused by this method is significantly reduced, the blistering of the synthetic fiber cloth can be minimized, and the precision of the concrete body can be improved.

In addition, the water-permeable synthetic fiber fabric expels water and air but does not expel cement particles, reducing the incidence of pockmarking on the concrete surface and ensuring the surface is dense and has sufficient strength and durability. A concrete structure having the following characteristics is obtained.

[Brief explanation of drawings]

Figures 1 to 3 show embodiments of the present invention; Figure 1 is a plan view, Figure 2 is an enlarged cutaway end view taken along the line ■-■ in Figure 1, and Figure 3 is a cross-sectional view of the Action explanatory diagram similar to the figure, 4th
The figure is an explanatory view of the operation similar to FIG. 3 using a plastic sheet. 1... Reinforcing bars, 3... Reticular body, 4 Synthetic fiber cloth tube Figure Figure Figure Figure

Claims (1)

[Claims] 1. A mesh body (3
) is laminated with water-permeable synthetic fiber cloth (4) from the front and back. 2. A mesh body (3) formed by crisscrossing reinforcing bars (1) vertically and horizontally.
) with a water-permeable synthetic fiber cloth (4) attached to one side. 3. The water-permeable synthetic fiber cloth (4) has 50 to 150 monofilaments of 45 to 55 deniers as weft threads, and 65
The simple formwork covered with water-permeable fabric according to claim 1 or 2, which is a plain woven fabric woven with 50 to 180 monofilaments of ~75 deniers as warp yarns.