JPH02267143A - Cement product reinforced with high strength fibers and production thereof - Google Patents

Abstract

PURPOSE:To obtain concrete products of high strength and satisfactory flame retardancy by using fibers reinforced by adhering a paste mainly containing a cement substance, a ultrafine powder and a high-performance water-reducing agent to the fibers. CONSTITUTION:The fibers for reinforcing concrete are coated with a paste mainly containing a cement substance, an ultrafine powder, and a high performance water-reducing agent by the hand lay-up method or impregnation. The reinforcing material is used in a single form or as a matrix-reinforcing material mainly containing water-hardening substance such as cement. Thus, fiber- reinforced cement products having high strength and satisfactory flame retardancy are obtained without hazardous asbestos.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a high-strength fiber-reinforced concrete product and a method for producing the same.

<Conventional technology and its problems> Conventionally, fiber-reinforced concrete products such as roofing materials, wall materials, and blocks are made by laminating nets made of asbestos, alkali-resistant glass fiber, etc., and fibrillated organic films. is known to be very useful as a reinforcing fiber.

However, since asbestos is a source of pollution, it is strongly desired to ban the use of fiber-reinforced concrete products that use asbestos, and environmental regulations are also being tightened.

Alkali-resistant glass fibers and ceramic fibers are available as TAM to replace asbestos, but these fibers are extremely expensive.
There was a problem that it was difficult to use it for building materials or concrete products from an economical point of view (Encyclopedia of Glass, 198
Published by Asakura Shoten, etc.).

Additionally, since organic fibers such as pulp and synthetic fibers have smooth surfaces, they can come off when stress is applied, and they are flammable, so adding them in large amounts will inhibit their flame retardancy as building materials. There was an issue of being exposed.

On the other hand, various methods are being considered to improve the strength of the cement itself, which is the matrix, but basically they lower the water-cement ratio and reduce the voids, which causes problems such as explosions during fire resistance tests. Ta.

Furthermore, it has been proposed to use a laminated net made of fibrillated organic film as reinforcing fibers (Japanese Patent Publication No. 55-46868), but the actual bending strength has not been improved, and the fiber content has not been improved. There were problems such as poor fire resistance due to the large amount of

As a result of various studies to solve the above problems, the present inventors have found that by using reinforcing fibers to which a kneaded material containing a specific composition as a main component is attached as a reinforcing material, it is economically superior and eliminates the use of asbestos. The present invention was completed based on the knowledge that a high-strength fiber-reinforced concrete product having high strength comparable to that of fiber-reinforced concrete products and sufficient flame retardancy can be obtained.

Means for Solving the Problems> That is, the present invention provides a high-strength fiber-reinforced concrete product made of reinforcing fibers to which a kneaded material containing cementitious material, ultrafine powder, a high-performance water reducing agent, and water as the main components is attached. The present invention will be described in detail below as a method for manufacturing the product.

The cementitious materials (hereinafter referred to as cement materials) used in the present invention include various types of por 1 to land cements such as normal, early strength, super early strength, white, and sulfate resistant, and these portland cements, as well as slag and fly ash. Cement 1-1, such as mixed cement, is a mixture of these various cements and Boblan reactive substances (hereinafter referred to as pozzolans) and latent hydraulic substances (hereinafter referred to as latent substances).

Pozzolanic substances are substances that contain reactive silicic acid that can be hardened together with calcium hydroxide, such as lye ash,
These include whitebait balloons, rice husk ash, blast furnace slag, etc., or a mixture thereof.

The latent material is, for example, a material such as blast furnace slag that does not exhibit hydraulic properties by itself, but becomes strongly hardened when used in combination with a stimulant such as an alkali.

As the stimulant, one or more of various types of cements, calcium hydroxide, slag, etc. can be used.

The amount of pozzolanic material or latent material to be used is generally preferably 5 to 95 parts by weight, and more preferably 40 to 60 parts by weight from the viewpoint of strength development and explosion prevention.

The particle size of cement is not particularly limited, but
The average particle size is usually about 10 to 30 microns.

The ultrafine powder used in the present invention has an average particle size that is at least one order of magnitude lower than that of cementitious powder, and in particular, from the viewpoint of fluidity of the kneaded product, one that has an average particle diameter of two orders of magnitude lower is preferable.

Specific examples include calcium carbonate, silica gel, opal silica, fly ash, slag, titanium oxide, and aluminum oxide. In particular, silica dust (which is a by-product when manufacturing silicon, silicon-containing alloys, and zirconia) It is preferable to use crushed and classified products such as silica fume), siliceous dust, and blast furnace slag.

The amount of ultrafine powder used is preferably 3 to 40 parts by weight based on 97 to 60 parts by weight of the cement. If it is less than 3 parts by weight, it is difficult to obtain high strength and high adhesiveness, and if it exceeds 40 parts by weight, the fluidity of the kneaded product decreases, it is difficult to obtain a molded product, and the strength development tends to be insufficient. be.

High performance water reducing agent used in the present invention (hereinafter referred to as the present water reducing agent)
is a surfactant with a large dispersion ability that does not cause too much delay in condensation or excessive air entrainment even when added in large amounts, and is a surfactant with a large dispersion ability that does not cause excessive condensation delay or excessive air entrainment. Examples include those whose main components are salts, high molecular weight lignin sulfonates, polycarboxylate salts, and the like.

This water reducing agent is necessary to obtain a kneaded product with a low water ratio, and the conventional amount used was 0.3 to 1 part by weight in terms of solid content per 100 parts by weight of cement. However, in the present invention, it is preferable to add it in a larger amount. Specifically, a mixture of cement and ultrafine powder (hereinafter referred to as powder)
The amount is at most 10 parts by weight in terms of solid content per 100 parts by weight, and if it is used in a larger amount, it will have an adverse effect on the curing reaction (there is a problem with the amount of spraying).

In addition to the above-mentioned materials, inert inorganic powder (hereinafter referred to as inorganic powder) or aggregate can be used as necessary.

There are no particular restrictions on the components of the inorganic powder, and oxide and non-oxide ceramic powders can be used. Specifically, there are silica, alumina, mullite, magnesia, spinel, silicon carbide, various nitrides, etc. Considering economic efficiency, it is preferable to use fine mineral powder such as stone powder.

Further, the aggregate used in the present invention is not particularly limited, but a harder aggregate is preferable.

In particular, Mohs hardness is 6 or more, preferably 7 or more, or Knoop indenter hardness is 700 kg/mm2 or more, preferably 8
It is preferable to use one selected on the basis of any criterion of 00 kg/m+n2 or more from the viewpoint of significantly improving the strength.

Those that meet the above criteria include silica, emery,
Examples include pyrite, magnetite, pyrite, lawsonite, corundum, zenasite, and spinel.

Furthermore, in addition to the above-mentioned materials, materials commonly used in concrete 1-, such as expansive materials, hardwoods, hardwoods, and shrinkage reducing agents, etc.
Alternatively, it is also possible to use admixture materials such as various chemical admixtures.

The reinforcing material used in the present invention is a reinforcing fiber formed by adhering a kneaded material containing the above-mentioned material as a main component.

The reinforcing fiber components may be those commonly used.
Examples include natural or synthetic organic fibers such as vinylon, polypropylene, polyethylene, acrylonitrile, aramid, and cellulose; metal, natural, and synthetic mineral fibers such as steel, stainless steel, and alumina; and carbon fibers.

In addition to chopped fibers, reinforcing fibers can be used in fiber aggregates such as nets, rods, cloaks, and woven fabrics. From this point of view, net-like products are preferable, and from the viewpoints of reinforcing effect, weight reduction, and economic efficiency,
Net-like products of organic fibers are particularly preferred.

The amount of reinforcing fiber used is 100 parts by volume of a composition whose main component is a hydraulic substance in a high-strength fiber-reinforced cement product.
The amount is preferably 10 parts by volume or less, more preferably 5 parts by volume or less, and most preferably 2 parts by volume or less.

Furthermore, in the present invention, the reinforcing fibers to which a kneaded material is attached are reinforcing fibers in which the kneaded material is present on the surface or in gaps of the reinforcing fibers.

Possible methods for applying the kneaded material include the Handley-Arnob method, impregnation method, roll rolling method, and press molding method.

The Handley Atsushi method is, for example, cutting reinforcing fibers such as net and laying them on a mold, and then placing the reinforcing fibers over the reinforcing fibers.
This method involves applying the kneaded material with a brush or roller.

The impregnation method is, for example, a method in which reinforcing fibers are immersed in a container containing a kneaded material, and the kneaded material is attached to the reinforcing fibers.

Additionally, the roll rolling method and press molding method are methods in which a kneaded material is brought into contact with the reinforcing fibers and rolled with rolls or pressure is applied with a press to eliminate gaps between the fibers and strengthen the adhesion. It is.

The reinforcing material may be used alone, and if necessary, a matrix mainly composed of a hydraulic substance such as cement may be used on both sides or one side of the reinforcing material, or the reinforcing material may be used on both sides of the matrix. can be placed in

The matrix is not particularly limited, and in addition to cement products obtained by ordinary pour molding, extrusion molding, paper making, dry pressing, etc., it is also possible to use ALC, etc., and if necessary, fibers etc. can also be blended.

Furthermore, in the present invention, a kneaded material containing a large amount of aggregate may be used.

M) The method for forming the IJ sock reinforcing material is generally to integrate it before curing, but it is also possible to integrate it again after curing using a kneaded material or an adhesive.

<Example) Hereinafter, the present invention will be explained in more detail by giving examples.

Example 1 60.3 parts by weight of cement-A, 13.7 parts by weight of ultrafine powder, 1.6 parts by weight of this water reducing agent and 16.4 parts by weight of water were kneaded using an omni mixer manufactured by Chiyoda Giken Kogyo ■. A kneaded material was attached using the reinforcing fiber shown in Figure 1 by the Handley Amplifier method to obtain a reinforcing material.

Cement material-A39.1 parts by weight, cement material-B33.
The reinforcing material was sandwiched between 7 Tricks made using 4 parts by weight, 16.7 parts by weight of aggregate, and 10.8 parts by weight of water,
A plate-shaped body having a length of 90 cm, a width of 45 cm, and a thickness of 0.5 cm was formed by press molding at a press pressure of 100 kg/cm 2 , and cured and hardened by a conventional method, and the bending strength was measured. For comparison, a similar test was conducted by molding and curing without sandwiching the reinforcing material. The results are also listed in Table-1.

Table-1 Bending strength (kg/cm”ゝゝゝゝ〈Materials used〉) Cement material-8: Manufactured by Union Cement Co., Ltd., Early strength Portland cement B: Manufactured by Electric Power Development Co., Ltd., Lightning fly ash: Manufactured by Nippon Heavy Industries, Ltd., Silica hume: No.-8 Manufactured by Kogyo Seiyaku Co., Ltd., product name [Cellflow 110PJ Main component C: Manufactured by Teikoku Sangyo Co., Ltd., inorganic-containing polypropylene net TR-11/12 D: Manufactured by Toyo Kagaku Co., Ltd., polypropylene net prototype E: Manufactured by Kanebo Co., Ltd., vinylon net Toughbell A-5300 F: Manufactured by Nippon Petrochemical Co., Ltd., polyethylene net warif MS-28: Crushed sand: Tap water ultra-fine powder, water reducer, reinforced fiber aggregate, water <Effects of the invention> The present invention eliminates the presence of harmful asbestos. , has high strength,
Furthermore, it has become possible to provide a high-strength fiber-reinforced cement product that has sufficient flame retardancy.

Claims (2)

[Claims] (1) A high-strength fiber-reinforced concrete product made of reinforcing fibers to which a kneaded material containing cementitious material, ultrafine powder, high-performance water reducing agent, and water as the main components is attached. (2) A method for manufacturing a high-strength fiber-reinforced concrete product, which comprises using the reinforcing material according to claim 1.