JPH06240861A - Framework for concrete and construction of concrete building wall - Google Patents

Abstract

PURPOSE:To improve durability, strength and releasing property from concrete by providing ribs and flanges on the rear surface of a concrete framework comprising a fiber reinforced resin layer and a urethane-based polymer layer. CONSTITUTION:Ribs (a) and flanges (b) are provided on the rear surface of a concrete framework comprising a fiber reinforced resin layer containing thermosetting resin and fiber reinforced material and an urethane-based polymer layer as a surface layer. As the urethane-based polymer, polyurethane having the stretchability of 10-300% is used. The thickness of the layer is made to be 0.3-2mm. In the construction of the wall of the concrete, the frameworks are alinged in parallel at an interval and fixed so that the urethane-based polymer layers of both frameworks face to each other. The concrete material is made to flow into the gap, and the frameworks are removed after the solidification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete formwork characterized in that a urethane-based polymer layer is integrally molded on the surface of a fiber reinforced resin panel.
It is useful as a concrete formwork in construction and civil engineering.

[0002]

2. Description of the Related Art Conventionally, a formwork for a concrete wall of a building has been mainly made of plywood, but it is easy to rot and has low durability. However, there are many important drawbacks such as poor workability and time required for assembly using nails and the like and skill in assembly. Therefore, a FRP mold is conventionally known as a mold for concrete that has improved durability and excellent dimensional stability by improving these drawbacks.

[0003]

However, this FRP mold is generally made of E-glass type glass fiber as a reinforcing material, and since it is inferior in alkali resistance, it is concrete-cast. As the construction and construction are repeated, the alkaline component in the concrete deteriorates, the strength and rigidity of the FRP decrease, and the surface of the form becomes rough, so the peelability of the concrete deteriorates. It was

[0004] The problem to be solved by the present invention is that it is extremely excellent in durability and strength, and has a significantly improved peeling property from a concrete wall, and that it can be easily assembled and disassembled. It is intended to provide a method for constructing a concrete wall of a building, which further improves workability.

[0005]

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by compositely integrating a urethane-based polymer layer on the surface of a fiber-reinforced resin layer and completed the present invention. Came to do.

That is, according to the present invention, a concrete formwork comprising a fiber reinforced resin layer and a urethane polymer layer as a surface layer, and the formwork are arranged in parallel at intervals and The present invention relates to a method for constructing a concrete building wall, which comprises fixing urethane type polymer layers of a mold so that they face each other, injecting a concrete material into the gap, solidifying the material, and then removing the mold.

Next, the present invention will be described in detail. The fiber-reinforced resin layer used in the present invention is not particularly limited, but is a thermosetting resin such as unsaturated polyester resin, vinyl ester resin, epoxy resin, urea resin, phenol resin, or vinyl chloride. Fiber-reinforced thermoplastic resins such as resins, polypropylene resins, polyethylene resins and nylon resins may be used. Among these, thermosetting resins are preferable because they are excellent in dimensional accuracy and strength during molding, and unsaturated polyester resins are particularly preferable because they are excellent in strength and productivity.

As the fiber reinforcement, glass fiber,
Examples thereof include carbon fibers and aramid fibers, but are not limited thereto. Among these, it is preferable to use glass fiber and carbon fiber in combination, because the rigidity of the fiber-reinforced resin layer is further improved.

The blending ratio of the fiber reinforcing material is not particularly limited and is usually in the range of 25 to 70% by weight, but 50 to 7 if particularly high strength and rigidity are required.
It is preferably 0% by weight.

The fiber reinforced resin layer may be molded by a hand layup method, a resin injection method,
It can be molded by using a preform matched die method, an SMC pressing method or the like, but a press molding method using SMC (sheet molding compound) is preferable in view of moldability of ribs and flanges, dimensional stability, productivity and the like. In addition, high strength SMC can be used to increase strength and rigidity.

On the other hand, as the urethane-based polymer layer used in the present invention, any known and commonly used curable polyurethane resin can be used and is not particularly limited. For example, a so-called urethane elastomer which is an elastic body can be used. A rigid polyurethane resin having a high cross-linking density and high rigidity may be used, but the latter is preferable because of its excellent strength upon curing and its excellent releasability from concrete.

The urethane elastomer is, for example, a polyisocyanate compound such as polyisocyanate having two or more free isocyanate groups in the molecule, or a polyisocyanate such as diisocyanate or diphenylmethane diisocyanate. A free isocyanate group in the molecule obtained by reacting a compound with polypropylene ether polyol having two or more hydroxyl groups, polyethylene propylene ether polyol or polyester polyol is 2 Urethane prepolymer containing more than one
By reacting a single chain glycol such as ethylene glycol or propylene glycol, or a long chain polyol having a molecular weight of 200 to 5,000 or a compound having active hydrogen such as polyamines. The known two-component system obtained may be used.

The reaction ratio between the urethane prepolymer and the compound having active hydrogen is 0.5 to 1 in terms of an equivalent ratio of free NCO in the urethane prepolymer / active hydrogen in the compound having active hydrogen. A range of 0.5 is preferable.

The rigid polyurethane resin having a high cross-linking density is not particularly limited, but has an elongation of 1
A polyurethane resin of 0 to 300% is preferably mentioned,
Among them, those having an elongation of 10 to 100% are preferable because they have excellent strength and low brittleness.

As such a rigid polyurethane resin having a high crosslinking density, for example, a polynuclear polyol containing a polyol-type xylene-formaldehyde resin having two or more hydroxyl groups as an essential component and two or more free-radicals in the molecule. The thing which made the polyisocyanate compound which has an isocyanate group into an essential component is mentioned.

The polynuclear polyol is composed of a polyol type xylene formaldehyde resin alone or a mixture of the resin and another polyol. The polyol-type xylene-formaldehyde resin is obtained by reacting meta-xylene and formalin under a strong acid catalyst.
Specifically, meta-xylene has a multi-molecular structure in which a xylene nucleus and a methylol group or a methoxymethyl group are linked to each other by a methylene bond, an acetal bond, or an ether bond and the molecule has a high reactivity in xylene resin In addition to the above-mentioned bonding groups and terminal groups, phenols, carboxylic acids,
Examples thereof include one type of a compound having active hydrogen such as amine and alcohol, or a compound modified by introducing a complex as a third component.

Such a polyol-type xylene-formaldehyde resin has 10 or less nuclides and 2 hydroxyl groups.
It is preferable to have one or more hydroxyl group equivalents of 50 or more,
Those having 2 to 4 nuclides are more preferable.

The third component used for modifying the xylene resin is, for example, trimethylolpropane, hexanediol, hexanetriol, polyoxyalkylene ether polyol, dipropylene glycol,
Examples thereof include ethylene glycol, diethylene glycol, glycerin, polybutadiene polyol, neopentylglycol, polychloroprene polyol, polycaprolactone polyol, phenol, alkyl alcohol, triethanolamine, pentaerythritol, and the like, with trimethylolpropane being preferred.

Such a polyol-type xylene resin tends to become stiffer as its number of functional groups increases, and its elongation tends to decrease.
In order to make it 00%, it is preferable that the number of functional groups is in the range of 2 to 4.

As the polyol other than the xylene resin in the polyol type xylene resin component, any of known and commonly used polyols can be used. Polyols,
Castor oil, soybean oil-modified polyol, castor oil-modified polyol and the like can be mentioned, and polyoxyalkylene ether polyol and castor oil are preferable. The polyoxyalkylene ether polyol has a hydroxyl group equivalent of 100.
The thing of -1000 is preferable.

Examples of the polyisocyanate compound having two or more free isocyanate groups used in the present invention include 2.4 and 2.6-toluene diisocyanate (TDI), diphenylmethane 4,4'-diisocyanate (pure). Or monomeric MDI), polymeric MDI, crude MDI, hexamethylene diisocyanate (HDI), trans-cyclohexa-
1.4-diisocyanate (CHDI), isophorone diisocyanate (IPDI), m-xylene diisocyanate (XDI), naphthalene diisocyanate (ND)
I), p-phenylene diisocyanate (PPDI),
4.4'-Diphenylmethane triisocyanate (Desmodur RI), NCO-terminated prepolymer (prepolymerization) of these isocyanate compounds and active hydrogen-containing compounds, and polyisocyanate compounds such as modified polyisocyanates liquefied by carbodiimidization Is.

The polyisocyanate compound is preferably polymeric MDI.

The thus obtained rigid polyurethane resin having a high cross-linking density is excellent in strength, but it is preferable that the Shore-D hardness is 60 or more.

The composite integral molding method of the urethane polymer layer and the fiber reinforced resin layer is not particularly limited, but a method of coating the urethane polymer after molding the panel forming the fiber reinforced resin layer or A method in which the fiber-reinforced resin layer is formed on the urethane-based polymer after sheet-forming is preferable. From the point of excellent adhesion between the urethane-based polymer and the fiber-reinforced resin layer and peelability from the concrete as a form, excellent durability, a method of coating and molding the urethane-based polymer after molding the panel forming the fiber-reinforced resin layer preferable.

In this case, in order to enhance the adhesion between the fiber reinforced resin layer and the urethane polymer layer, the surface of the fiber reinforced resin layer is subjected to uneven processing, or after the fiber reinforced resin layer is molded, the surface is sanded. It is preferable.

The thickness of the urethane polymer layer is not particularly limited, but is 0.3 to 2 mm,
It is preferable because it has excellent releasability from concrete and the weight of the form can be reduced.

The thickness of the fiber reinforced resin layer is not particularly limited and is usually 3 to 7 mm.

The formwork for concrete of the present invention can be used as it is in panel form as it is for pouring concrete using a support material, but ribs are provided on the back surface to reinforce the panel surface material, Optimum design of rib shape and significant weight reduction can be achieved. Further, by providing a flange all around the fiber reinforced resin layer panel, the panels can be easily joined and assembled.

The ribs and flanges may be provided after the panel is manufactured, but it is preferable to form the ribs and flanges by the composite integral molding described above.

The above-mentioned concrete formwork is useful as a concrete frame in construction and civil engineering, and its use is not particularly limited, but the effect of the present invention is sufficiently exhibited particularly in the construction of concrete building walls. It

The compressive strength of this concrete formwork is not particularly limited, but when constructing a concrete building wall with a height of 2 mm or more, 0.4 kg / c
It is preferably capable of withstanding a pressure of m ² or more.

As a method for constructing a concrete building wall using the mold of the present invention, the molds are arranged in parallel at intervals and fixed so that the urethane polymer layers of the mold face each other. , A method in which a concrete material is flown into the gap, and after the material is solidified, the form is removed.

More specifically, for example, a plurality of concrete form frames are arranged side by side in parallel at intervals, and the flanges of adjacent panels are joined using bolts or clips. Here, metal fittings such as nuts may be insert-molded on the ribs and flanges, and processing such as punching and notching may be performed as necessary. Further, it is preferable that the facing concrete formwork is fixed by a fixture such as a separator.

Then, concrete material is poured into the gap, and after the material is solidified, the form is removed, so that the concrete wall of the building can be constructed very easily, that is, without skill. it can.

[0035]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 A fiber reinforced resin layer made of a composition containing 55% by weight of glass fiber of an unsaturated polyester resin was used, and as shown in FIGS. 1 to 3, ribs and flanges were provided on the back surface. ,
Holes having a diameter of 12 mm were formed on the periphery of each of the four flanges on each side, and the ribs were press-molded so that nuts were inserted. The obtained panel is 600 × 600 × 60H
(Mm), the thickness of the panel was 5 mm.

After the surface of the panel was sandblasted, polyurethane composed of a polyol type xylene formaldehyde resin and a polymeric MDI having a Shore-D hardness of 75 and an elongation of 55% was used. A urethane-based polymer layer having a thickness of 1 mm was formed.

(Manufacturing of concrete building wall) This formwork is joined three vertically and ten horizontally to form two 1.8 m × 6 m formwork.
Face assembled. The panels could be easily joined by using M10 bolts in the holes machined in the flange. Next, the insert-molded nut on the back surface was externally reinforced with bolts to fix the two-sided molds in parallel.
After the concrete was placed and cured in the meantime, the form was removed and the wall was constructed. Sufficient mold strength was obtained for placing concrete, and removal of the concrete was particularly good, and work was easy. Although it was used 30 times repeatedly, no noticeable change was observed and a system mold having durability could be obtained.

Comparative Example 1 A concrete formwork was produced in the same manner as in Example 1 except that the urethane polymer layer was not formed.

Then, a concrete building wall was manufactured in the same manner as in Example 1. However, the fiber reinforcing material of the mold was exposed after 10 times of repeated use, and the concrete came to adhere to the mold. I can no longer use it.

[0041]

Industrial Applicability According to the present invention, the durability and strength are remarkably excellent, and the releasability from concrete is remarkably improved, so that the present invention can be widely used for civil engineering and construction.
Especially when it is used for building walls, it does not require skill because it is lightweight and can significantly improve the work environment, can be systemized and unitized, and has excellent durability. Moreover, it has an advantage that it can be used for a long period of time.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a concrete formwork of the present invention.

FIG. 2 is a sectional view showing an example of a concrete formwork provided with ribs and flanges.

FIG. 3 is a sectional view of a panel portion of a concrete formwork of the present invention a: rib b: flange A: fiber-reinforced resin layer B: urethane-based polymer layer

Claims (7)

[Claims] 1. A concrete formwork comprising a fiber reinforced resin layer and a urethane polymer layer as a surface layer. 2. The urethane polymer has an elongation of 10 to 300.
The mold of claim 1 which is% polyurethane. 3. The mold according to claim 2, wherein the fiber reinforced resin layer contains a thermosetting resin and a fiber reinforced material. 4. The thickness of the urethane polymer layer is 0.3 to.
The mold according to claim 3, which has a length of 2 mm. 5. The formwork according to claim 1, further comprising a rib and a flange on the back surface. 6. The formwork according to claim 5, which is used during construction of a concrete wall of a building. 7. The molds according to claim 6 are arranged in parallel at intervals, and the urethane-based polymer layers of the molds are fixed so as to face each other, and a concrete material is flown into the gaps to form the material. A method for constructing a concrete building wall, which comprises removing the formwork after solidification of the concrete.