JPS6332062A - Concrete mold frame - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to formwork used in constructing concrete structures.

[Prior art]

Traditionally, wood, particularly veneer plywood, has been used as formwork for constructing concrete structures. However, veneer plywood has disadvantages in that it is susceptible to water and deforms, and that the poured concrete adheres to the formwork, making it difficult to clean it and making it impossible to use the same formwork over and over again.

Recently, iron plates with lips and resin formwork have become popular as formwork that can be used many times.

[Problems to be solved by the present invention]

However, compared to those made of plywood, these formworks do not have the ability to absorb moisture in concrete and dissipate it into the atmosphere, which delays concrete hardening and takes longer to demold. Its spread is delayed.

Formwork with many small holes is used as a measure to make it easier for moisture in the concrete to escape to the outside, but the holes reduce the strength of the formwork, and This method has the disadvantage that the cement content in concrete and cleat, and depending on the size of the hole, can be discharged along with the water, which poses a problem for practical use.

[Means for solving problems]

The formwork of the present invention is made of concrete by using a formwork whose surface is coated with an air-permeable resin film with a communicating body (herein, a communicating body refers to a member that can seep in and permeate water) as a backing material. The purpose of the present invention is to provide a formwork that releases only the moisture generated as water vapor out of the moisture contained therein to the outside, thereby speeding up the hardening of poured concrete and shortening the construction period.

The present invention will be described in detail below.

The breathable resin film used in the present invention has been recently developed and is used as a main material for lithium batteries, uranium 67 tsunide separation membranes, gas separation membranes, reverse osmosis membranes, etc.

Alternatively, it is used as a material that does not leak water or become stuffy, such as in baby diapers.

These breathable resin films are known to be made of polyolefins such as polyethylene, polypropylene, and polyfluoroethylene, polyamides, and polyurethanes, and are generally stretched at a temperature below the melting point.

It is manufactured by mixing these resins with a filler that is soluble in a solvent to form a film, and then extracting the filler. The water resistance of these coatings is typically 500 tea H
20 or more (JIS-L-1092, A method, static pressure method). 2 Air permeability is usually 100'-100 in terms of moisture permeability.
0097m ・atm @24hr (ASTM-E-
96-66,32,2℃φ inside 100% a) r/outside 50%
In other words, it is a resin film that does not allow water to pass through, but allows water vapor to pass through.

This breathable resin film is usually a thin film of 5 to 500 μm, and is insufficient in rigidity and strength to be used as a concrete formwork. Therefore, a material with high rigidity is used as the backing material, but as mentioned above, iron plates and resin formwork do not have breathability, so the space between the thin and breathable resin film on the surface will stick together, and 2. Sexuality is inhibited and goals cannot be achieved.

Therefore, the present inventors developed open foams such as flexible polyurethane and flexible polyvinyl chloride, metals such as aluminum and iron, metal oxides such as alumina, and polyethylene.

Fiber materials and honeycomb structures made of resins such as polypropylene, polyamide, polyester, and polyurethane.

The problem was solved by interposing a thick, continuous layer of wood, plywood, etc. Some communicating bodies do not function as rigid bodies themselves, but in such cases, if a rigid body is further reinforced on the back, they can be used as concrete formwork.

Although these multilayer bodies can be used by simply stacking them on top of each other, it is easier to use them if they are laminated together and integrated.

However, simply laminating the entire surface with adhesive does not provide breathability due to the high waterproofness of the adhesive layer, so point adhesion is appropriate for laminating with the breathable resin film.

Further, by interposing a fiber layer between the breathable resin film and the communication body and bonding them by thermocompression, the properties of the film can be improved.

The fiber layer is polyethylene or polypropylene.

In addition to resins such as polyester, polyamide, polyurethane, and polyvinyl acetate, we also use copper, iron, and aluminum.

Non-woven fabrics, woven fabrics, perforated nets, etc. made of metals such as alumina and carbon, metal salts, or natural products, either alone or in blended fabrics.

Composite products etc. are used.

To bond the fiber layer and the breathable resin film, it is sufficient to press the resin in a molten state.In this case, the fiber layer can be entangled in the resin film even if the materials are not of the same quality, but the breathability of each must be kept as intact as possible.

Furthermore, if the communication body is soft, it is necessary to attach a rigid backing body to the body, but a common adhesive can be used for this purpose.

An embodiment of the concrete formwork of the present invention will be described below with reference to the accompanying drawings. Figure 1 shows the connecting body (2
), and Figure 1 shows the plan view of the small hole (4
) is shown in a synthetic resin honeycomb structure.

FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and an air-permeable resin film (1) is pasted on the surface of this communicating body.

FIG. 3 shows a coating film used in another embodiment.

The fiber layer (3) and the breathable resin film (1) are integrally constructed.

The breathable resin film (1) used here is polyethylene, polypropylene, or polyfluoroethylene.

5. Polyamide, polyurethane, etc. - It is a thin membrane of 500 μm and has a waterproof property of 500 rrrm.
H20 or higher 2 Air permeability is usually 100 to 10,000 in terms of moisture permeability.
It is a resin thin film that has physical properties of 97 m/atm/24 hr, and has the property of not allowing water to pass through it, but allowing water vapor to pass through it.

Further, as the communication body (2), foams such as flexible polyurethane and flexible polyvinyl chloride, metals such as aluminum and iron, metal oxides such as alumina, fiber materials of resins such as polyethylene, polypropylene, polyamide, polyester, and polyurethane, Honeycomb structure, wood.

Continuous structures such as veneer plywood are suitable, but there are also materials such as fibers and foams, which are not rigid in themselves and are not suitable for use in formwork. In some cases, if the back is further reinforced with a rigid body, it can be used as a formwork.

The laminate of the breathable resin film (1) and the communication body (2) can also be used by simply stacking them on top of each other.

It is easier to use if they are glued together to form a whole.

However, if the entire surface is simply pasted together with adhesive, the adhesive layer is highly waterproof and breathability cannot be obtained. It is preferable to use a backing material with communicating small holes (4) as shown in the figure, but when using a flat board such as plywood, point adhesion is appropriate for laminating it with a breathable resin film, taking into account breathability. There is a need.

When a fiber layer is interposed between the membrane (1) and the communication body (2), the fiber layer may include polyethylene, polypropylene,
polyester, polyamide, polyurethane.

In addition to resins such as polyvinyl acetate, iron, copper, and aluminum.

Non-woven fabrics, woven fabrics, perforated nets, etc. made of metals such as alumina and carbon, metal salts, or natural products, single articles, blended articles, vi-metal articles, etc. can be used. In order to bond such a fiber layer (3) and the breathable resin film (1), it is sufficient to press the resin in a melted state, and in this case, even if the material is not necessarily of the same quality, the fiber layer may be bonded within the resin film. However, it is necessary to avoid impairing the breathability of each part as much as possible.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 A polypropylene honeycomb formwork with a thickness of 50 cm was placed on the inner four sides and bottom of a polypropylene honeycomb formwork with internal dimensions length 10 cr + width 10 sub-height 20 m.
μm breathable polyethylene film (moisture permeability 1600
f/g @ * a tm ・24 hr water pressure 20
00 ttrm H20 or more) and a polyester nonwoven fabric (6097 m, thickness approximately 1 cm) heat-welded to the sheet.
After heat welding and integrating with the film surface as the contact surface, Portland cement mortar (w/c=0.6, s/c
= 2, 3 = silica sand No. 4) was poured. This was left indoors and its weight was measured over time to confirm moisture release from the formwork.

The measurement results are shown in Figure 1.

Comparative Example 1 In place of the breathable polyethylene film in Example 1, a non-breathable polyethylene film with a thickness of 50 μm (moisture permeability 8?/m ・atm ・24 hr) was used.
2, and the results of the 0 measurement conducted in the same manner as in Example 1 are also shown in Figure 1.

[Effects of the present invention]

In the concrete formwork of the present invention, the poured concrete comes into contact with the breathable resin film, and as the temperature rises during the day, excess water is released through the film as water vapor through the communicating body to the outside. As the water required for hardening of cement remains in the concrete, it can be expected to accelerate the hardening of concrete and shorten the construction period, which is extremely advantageous for construction in northern countries where construction period is short. There is no problem because only excess water is released.

In addition, there is no concrete remaining on the formwork even after the concrete has hardened, making post-treatment of the formwork easy, and the dry hardening of the concrete can be gradually evened out, which can be expected to improve the physical properties of concrete. The effect is extremely important in the construction of concrete structures.

[Brief explanation of the drawing]

Figure 1 shows a plan view of the communicating body as a backing material, and
The figure shows a sectional view taken along line A-A in FIG. Further, FIG. 3 shows a sectional view of a coating film according to another embodiment. (1)...Breathable resin film (2)...Connector (3)...Fiber layer (4)...Small hole patent applicant Mitsui Toatsu Chemical Co., Ltd. and one other person

Claims (2)

[Claims] (1) A concrete formwork characterized in that the surface is coated with an air-permeable resin film using a communicating body as a lining material. (2) The concrete formwork according to item 1, wherein the communicating body and the breathable resin film are bonded to each other via a fiber layer.