JPH0363107A - Form material and buried form using same and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain the incombustibility of form the same as that of the form, in which metal-based or ceramic-based form material is used, while the workability at site is held, by a method wherein a buried form is made of form material, which mainly consists of calcium silicate, latex and fibrous material. CONSTITUTION:Calcium silicate, which is prepared by drying slurry obtained through hydrothermal synthesis, powered latex, which is prepared by drying latex emulsion with a spray drier or the like so as to be re-emulsified in contact with water, fibrous or powder dispersant, polymeric flocculant or the like in dry state are uniformly mixed with on another. The general forming method used is the dehydration or filtration of slurry under pressure. The form obtained by the above-mentioned method does not impair the incombustibility of concrete even under the condition of being imbedded in concrete and consequently the fire resistant properties of concrete can be maintained, though the form concerned is a simple form and can be easily worked at building site.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to formwork materials used when pouring concrete, particularly for making circular or polygonal through holes or depressions in concrete, This invention relates to a formwork material for an embedded formwork used to curve a surface, an embedded formwork using the same, and a manufacturing method thereof.

(Prior art and its problems) Conventionally, the formwork materials used when pouring concrete are generally wood-based materials, paper-based materials, metal-based materials, ceramic-based materials, and the like.

However, at construction sites, the only formwork that can be easily cut, drilled, nailed, etc. is the only formwork that uses wood-based or paper-based formwork materials; Formwork using other formwork materials other than the frame material is
It is almost impossible to carry out the above-mentioned processing on-site, it is difficult to carry out corrections and modifications based on on-site adjustments, and a formwork with high dimensional accuracy is required, which is a problem that cannot necessarily be called a simple formwork.

On the other hand, formwork using wood-based or paper-based formwork materials is a simple formwork because it can be processed on-site. The frame is easy to use.

In particular, for through holes for equipment piping and through holes for air conditioning, etc.
A formwork made of paper-based formwork material is commonly known as a void tube.

However, wood-based and paper-based formwork materials are easily flammable, so it is not desirable for disaster prevention to leave formwork made from them in concrete as buried formwork, and it is not recommended for fire prevention zones, etc. From this point of view, there was an issue that legal standards could not be met.

Therefore, when using formwork made of these formwork materials for boat fishing, it was necessary to remove the formwork after the concrete had sufficiently hardened. This work is easy on flat surfaces such as concrete columns, beams, floors, and walls, but it is quite difficult when there are through holes or curved surfaces inside concrete columns, beams, floors, and walls. He was very thorough.

Furthermore, attempts have been made to use gypsum board, which is said to be a noncombustible material and relatively easy to process, for formwork (Japanese Patent Publication No. 1-30986).

However, in general, the bending strength of gypsum board itself is quite low at 20 to 30 kg/cm", so when using gypsum board as a formwork for pouring concrete, it is necessary to make the gypsum board considerably thicker or to It was necessary to place the reinforcing plate along the opposite side of the board from the concrete.

Increasing the thickness of the gypsum board is not only economically disadvantageous, but also causes problems in that the gypsum board itself loses its flexibility.

In addition, when placing a reinforcing plate along the opposite side of the gypsum board from the concrete, it is effective for a simple planar shape such as a wall, but it is also effective when placing a reinforcing plate along the opposite side of the gypsum board from the concrete. There was a problem in that it was quite difficult to fit the reinforcing plate along complex-shaped parts such as the connecting parts.

Moreover, since reinforcing plates must be removed from penetrations and curved surfaces after the concrete has hardened, this is no different from using wood-based or paper-based formwork materials.

In order to solve the above problems, the present inventors have conducted various studies and found that by using a specific material, the on-site processing of formwork using wood-based or paper-based formwork materials is improved. The present invention was completed based on the knowledge that it is possible to obtain an embedded formwork that is easy to use and has the nonflammability of formwork made of metal or ceramic formwork materials.

<Means for Solving the Problems> That is, the present invention is a formwork material whose main components are calcium silicate, latex, and fibers, an embedded formwork using the same, and a method for manufacturing the same.

The present invention will be explained in detail below.

The calcium silicate used in the present invention is not particularly limited, but it is preferably one obtained by a hydrothermal synthesis reaction using a calcareous raw material, a silicate raw material, and water, and those called xonotlite or tobermorite are preferred. preferable.

The blending ratio of the calcareous raw material and the silicic raw material varies depending on the calcium silicate base, but in the case of xonotlite, the Cab/Sing molar ratio is preferably approximately 1/1;
It is not limited to this.

The latex used in the present invention is one that combines calcium silicate and fiber. Specifically, ethylene-vinyl acetate copolymer, self-crosslinking acrylic acid ester polymer, styrene-butadiene copolymer, acrylonitrile-
Butadiene copolymers, butadiene polymers, methyl methacrylate-butadiene copolymers, isoprene polymers, ethylene-prohylene copolymers, chloroprene rubber latex, and the like can be used.

The amount of latex used is preferably 1 to 40 parts by weight in terms of solid content per 100 parts by weight of calcium silicate. If the amount is less than 1 part by weight, there will be problems in processability, and if it exceeds 40 parts by weight, there will be problems in nonflammability.

The fibers used in the present invention include, but are not limited to, fibers such as glass fiber, cotton, kraft pulp, rayon, polypropylene, polyethylene, vinylon, and nylon.

The amount of fibrous material to be used is not particularly limited from the viewpoint of physical properties as a formwork material, but from the viewpoint of moldability, calcium silicate 10
It is preferably 1 to 30 parts by weight relative to 0 parts by weight.

When creating a form using the form material of the present invention whose main components are calcium silicate, latex, and fibrous material, a dispersant, a polymer flocculant, blast furnace slag, fly ash, and silica fume are further added. Inorganic admixtures and fillers, such as, and organic admixtures such as water resistance imparting agents and water repellent agents can be used in combination.

Here, as the dispersant, any of anionic dispersants, nonionic dispersants, and cationic dispersants can be used.

For example, anionic dispersants include lignin, higher polyhydric alcohol sulfonates, oxyorganic acids, alkylaryl sulfonates or their high condensates, melamine condensates, β
- Naphthalene sulfonic acid formalin condensates and higher alcohol sulfate ester sodium salts.

Nonionic dispersants include poval, methyl cellulose,
Examples include polyoxyethylene, nonylphenyl ether, and styryl phenyl ether.

Examples of cationic dispersants include 2-acetyl methacrylate hydrochloride and 2-hydroxy-3-trimethylaminopropyl methacrylate chloride.

The amount of the dispersant used is preferably 0.1 to 10 parts by weight in terms of solid content per 100 parts by weight of calcium silicate. 0
．． If it is less than 1 part by weight, the effect of use is poor, and if it is used in excess of 10 parts by weight, there is no difference in the effect of use.

Furthermore, examples of polymer flocculants include quaternary amine compounds such as polydialkylaminoalkyl acrylate, polyaminomethyl acrylamide, polyvinyl pyridinium halide salts, and polyvinylimidapurine. Preferred are dialkylaminoalkyl acrylates and polyacrylamides such as polymethylacrylamide.

The larger the amount of polymer flocculant used, the higher the bending strength of the formwork, but the lower the nonflammability, so it is preferably 50 parts by weight or less, and 1 to 1 More preferably 30 parts by weight.

A method for manufacturing the embedded formwork of the present invention using the above materials will be explained.

The manufacturing process can be divided into three processes, for example, a mixing process, a molding process, and a curing process.

As the mixing process, both dry mixing and wet mixing are possible.

Dry mixing involves drying a slurry of calcium silicate obtained through hydrothermal synthesis, and then drying the latex emulsion using a spray dryer, etc. This process produces powdered latex that re-emulsifies when it comes into contact with water, as well as fibrous and powdered materials. This method involves uniformly mixing dispersants, polymer flocculants, etc. in a dry state. This method allows uniform mixing in a short time of about 10 to 30 minutes.

In wet mixing, latex, fibers, a dispersant, a polymer flocculant, and the like are added to a slurry of calcium silicate, and the mixture is mixed with stirring until a uniform slurry is obtained. This method does not require drying the calcium silicate slurry, which saves time and energy for drying.

Whether dry or wet mixing, it is important to obtain a homogeneous mixture.

A method for obtaining a molded body from a mold material that has become a homogeneous mixture will be described.

Even if the formwork material is obtained by dry mixing, it is preferable to add moisture and return it to a slurry form in order to fully exhibit the bonding power of the latex.

Forming methods include a method of dewatering the slurry while pressurizing it (pressure dehydration method), or a method of filtering it while applying pressure (pressure filtration method), which is used for boat fishing. There is also a method of separation and dehydration or filtration followed by pressure molding.Furthermore, there are also methods of dehydration or filtration followed by extrusion molding and centrifugal molding.In centrifugal molding, dehydration Alternatively, it is also possible to perform molding at the same time as filtration.

Pressurization conditions are not particularly limited, but 5 to 10
0kg/c+! is preferable, and 10 to 80 kg/cd is more preferable. If it is less than 5 kg/c4, sufficient strength of the molded article cannot be obtained, and if it exceeds 100 kg/c+j, there is a risk that the molded article will be crushed during pressurization.

In addition, the shorter the pressurizing time, the better from the viewpoint of formability, but at present, from the viewpoint of the strength of the molded product, at least 10
About a second is required, preferably 10 seconds to 30 minutes, more preferably 10 minutes or less. Even if the pressure is applied for more than 30 minutes, the strength of the obtained molded product hardly changes.

As an example of a molded product, when molding a cylindrical molded product,
A method of joining two pieces press-formed into semi-cylindrical shapes,
Possible methods include a method of applying pressure in the longitudinal direction, that is, a cylindrical direction, a method of centrifugal molding, a method of extrusion molding, a method of roller rolling from the inside of the cylinder to the outside, and a method of combining these methods.

In the case of these molding methods, dehydration or filtration can be carried out before molding, or can be carried out simultaneously with molding.

The curing process is a process of drying the calcium silicate molded body that has undergone the molding process.

Generally, hot air drying is used as a drying method. The drying temperature of hot air drying is preferably 80 to 180°C, and 10
0 to 150°C is more preferred. Below 80°C,
It takes a long time to dry, and sufficient drying cannot be expected. Furthermore, if the temperature exceeds 180°C, the latex will harden and the dried molded product will become brittle, which is not preferable.

Furthermore, other drying methods include a method of drying using microwaves, a method of vacuum or vacuum dehydration drying, and the like.

The longer the drying time, the more reliable the drying, so it is preferable, but it is usually within 24 hours, preferably 8 to 16 hours. Further, when using microwaves, drying can be performed in a shorter time.

<Example> Hereinafter, the present invention will be explained in detail based on examples.

Example 1 Calcium hydroxide and silicic acid powder were mixed into CaO/SiO□
They were blended so that the molar ratio was 171, and 14 times the weight of water was added to the total weight to form a slurry.

While stirring this slurry in an autoclave,
A hydrothermal synthesis reaction was carried out for 6 hours at 119 kg/c.

When the calcium silicate thus obtained was subjected to X-ray diffraction, more than 90% was found to be xonotrite.

This slurry was dehydrated to a water powder ratio of 9:l.

To this slurry were added ethylene-vinyl acetate copolymer as a latex, glass fiber as a fibrous material, and "Cellflow 110 P1" as a dispersant in the proportions shown in Table 1 in terms of solid content.

This calcium silicate hydrate mixed slurry was filled into a mold, and subjected to pressure filtration and dehydration at a pressure of 30 kg/cm.
A calcium silicate molded body was obtained by drying at °C for 24 hours. Regarding this molded body, bending strength according to JIS A 140B, workability determined by comparison with wood when processing operations such as nailing and sawing, and JIS A 1
The nonflammability was measured according to 321, and the table below along with the moldability
Also listed in 1.

The results are shown in numerical values and evaluations for bending strength, and evaluations for workability, nonflammability, and moldability.

An evaluation of O means good, △ means good, and × means bad.

<Materials used> Calcium hydroxide: Manufactured by Wako Pure Chemical Industries, Ltd. Reagent 1st class silicic acid powder Ni Tokai Kogyo ■Product name: “Izu Tokufunko J, Plain value 5.07
0 cTA/g, 5 tOz content 96.4% Latex: Ethylene-vinyl acetate copolymer, manufactured by Denki Kagaku Kogyo ■ Fiber: Chopped strand manufactured by Asahi Fiberglass ■, length 13 mm Dispersant: Daiichi Kogyo Seiyaku ■ Product name: “Selfflow ll”
0P J Main tc content β-naphthalenesulfonic acid formalin condensate Example 2 The calcium silicate slurry obtained in Example 1 was dehydrated to obtain a slurry with a water powder pressure of 2:1. With respect to 100 parts by weight of the solid content of this slurry, 20 parts by weight of styrene-butadiene copolymer latex, 4.0 parts by weight of glass fiber, and an acrylamide type polymer flocculant such as a cationic polymer flocculant. The same procedure as in Example 1 was carried out except that 2.0 parts by weight was added and sufficiently stirred and dispersed.

As a result, the bending strength was good at 105 kg/cm'', and the workability, nonflammability, and moldability were all good.

Example 3 Using the calcium silicate hydrate mixed slurry of Experiment No. 1-2 of Example 1, the inner diameter was 125 mm and the wall thickness was 5a+a.
+, a cylindrical embedded formwork with a length In was created.

After assembling the reinforcing bars of the concrete wall, the length is 200n.
After installing this buried formwork cut to +m in the position where the pipe will pass, create a frame with concrete formwork, pour ready-mixed concrete into it, and use this buried formwork to insert the pipe through the 200mm thick concrete wall. It was used as a through hole for After sufficient curing and confirmation that the strength of the concrete had reached the design strength, the concrete formwork was removed and the buried formwork was confirmed to be in its designated position. Thereafter, a hard PVC-lined steel pipe for water supply of size 80A was passed through this through-hole, and the gap was filled with mortar, thereby making it possible to install a water supply pipe that penetrated the wall.

Since this buried formwork was made of noncombustible material, it fulfilled its role as a fireproof zone even if it remained inside the concrete.

For comparison, a similar experiment was conducted using a void tube of the same size. This void pipe is flammable, so
In order to create a fireproof compartment, it must be removed, and the work of removing it is extremely difficult because the concrete hardens and shrinks, and the void pipe absorbs water and expands. It took a lot of effort.

Further, although the work after removing the void pipe was similar to that when using the buried formwork of the present invention, it required considerably more man-hours.

Example 4 Using the calcium silicate hydrate mixed slurry of experiment Nα1-3 of Example 1, the inner diameter was 75.100, 125.15.
0 opening and 150 to 1.000mm at 50ma + pitch,
, 1.100 mm and 1,2001 mm were created, and the same experiment as in Example 3 was conducted. Results Example 3
Similarly, good results were obtained.

Example 5 Using the calcium silicate hydrate mixed slurry of Experiment 1-2 of Example 1, a prismatic buried formwork with an inner diameter of 100 x 100 s+m and a wall thickness of 5 mm was created, and the mold was prepared as in Example 3. A similar experiment was conducted and similarly good results were obtained.

<Effects of the Invention> The present invention uses calcium silicate, which is a non-combustible inorganic material, as the main material, and by adding a polymer to this inorganic material and molding it, a buried formwork with processing performance is provided at a construction site. This is a formwork material for obtaining the material, and an embedded formwork using this material.

Therefore, although it is a simple formwork that can be easily processed at a construction site, it does not impair the non-combustibility of concrete even when buried in concrete, and has the effect of maintaining the fireproof performance of concrete. be.

In addition, considering that conventional, simple buried formwork using wood-based or paper-based formwork materials required the effort to remove the concrete after it hardened due to fire safety issues.
The embedded formwork of the present invention is also useful for simplifying the work process, and has the effect that it is possible to obtain a formwork that is simpler than conventional formworks.

Claims (3)

[Claims] (1) Formwork material whose main components are calcium silicate, latex, and fiber. (2) An embedded formwork formed using the formwork material according to claim 1. (3) kneading the formwork material according to claim 1 and water and applying pressure;
3. The method of manufacturing an embedded formwork according to claim 2, which comprises molding and curing.