JPH02102159A - Cement composition - Google Patents

Abstract

PURPOSE:To improve strength and impact resistance by containing edenite, an inorganic aggregate, reinforcing fiber and cellulosic admixture in a cement. CONSTITUTION:A cement composition obtained by blending 100 pts.wt. cement with 2-50 pts.wt. edenite, 10-100 pts.wt. spherical inorganic aggregate (e.g., fly ash) having 0.1-500mum particle diameter, 0.1-10 pts.wt. reinforcing fiber (e.g., PP) having 1-100mum diameter, 3-15mm fiber length, >=3g/d strength and >=50g/d Young's modulus and 0.1-10 pts.wt. cellulosic admixture (e.g., methyl cellulose).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to cement compositions, particularly floor materials used for decking materials for verandas and balconies, corridor materials for apartment complexes, and wall materials such as exterior walls of houses. The present invention relates to a cement composition suitable for producing.

(Prior Art) Asbestos-cement molded boards, which have relatively high strength and fire-retardant properties, are used as flooring materials such as decking materials for verandas and balconies and hallway materials for apartment complexes. This molded plate is manufactured by extrusion using a cement composition containing diasbestos. In the manufacturing process, asbestos increases the fluidity of the slurry cement composition and improves the shape retention of the extruded uncured molded body. Furthermore, it improves the strength of the final product obtained. However, the resulting molded product has the disadvantage of being weak against impact. Furthermore, the asbestos contained in it is designated as a specified chemical substance, and its carcinogenicity has become a problem. Although standards for use are established when asbestos cement molded bodies are manufactured, molded bodies using cement compositions that do not contain asbestos are currently desired due to the problem of dust generation during manufacture and use.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks, and its purpose is to provide a cement molded product that has high strength and impact resistance and does not contain harmful asbestos. An object of the present invention is to provide a cement composition that can be prepared.

(Means for Solving the Problems) The cement composition of the present invention contains 2 to 50 parts by weight of edenite and 10 to 10 parts by weight of inorganic aggregate based on 100 parts by weight of cement.
100 parts by weight, and 0.1 to 10 parts by weight of reinforcing fibers.

The cellulose-based admixture is contained in an amount of 0.1 to 10 parts by weight, thereby achieving the above object.

As the cement contained in the cement composition used in the present invention, any known cement such as Portland cement, blast furnace cement, and alumina cement may be used.

Edenite contained in the cement 1 composition belongs to inosilicate and is a rock-forming mineral having a double structure of 51g tetrahedrons. This Edenite is NaCaz Mg5Siy
It is denoted by AIOzz(OH)z. Edenite may be in the form of a fiber, a single grain of powder, or a plate. In particular, when fibrous edenite is used, the fluidity of the water-containing cement mixture during kneading and molding, the shape retention of the resulting uncured cement molded product, and the strength of the cured molded product are excellent. Edenite is contained in an amount of 2 to 50 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the cement. If the amount is too small, the fluidity during kneading and molding, the shape retention of the uncured molded product, and the strength of the cured molded product will be poor. If it is in excess, moldability will be poor. Edenite can also be dispersed in water in advance and mixed with cement etc. as an aqueous dispersion.

The inorganic aggregate contained in the cement composition is mainly composed of spherical particles, and the particle size thereof is 0.1 to 500 μm. Inorganic aggregates include fly ash (pulverized coal combustion ash collected in dust collectors at coal-fired power plants), microsilica, silica fume, spherical silicic acid silica 1, (by-product during the production of silicon metal, ferrosilicon, etc.) ) etc. are suitable. As the inorganic aggregate, a lightweight aggregate may be used depending on the use of the obtained cement molded body. As the lightweight aggregate, for example, materials described in JIS A3002 may be used. The inorganic aggregate is contained in the cement composition at a ratio of 10 to 100 parts by weight per 100 parts by weight of the cement. If the proportion of the inorganic aggregate in the entire composition is low, moldability will be poor, and if it is excessive, the strength of the molded product obtained will be reduced.

Reinforcing fibers are used to improve the bending strength and impact strength of the resulting molded product. For example, organic fibers, pulp, metal fibers, etc. can be used. As an organic fiber, the 2 strength is 3 g/d or more.

Alkali-resistant fibers having a Young's modulus of 50 g/d or more and an elongation of 3% or more are suitable. The above d indicates denier. Examples of reinforcing fibers include vinylon.

Polypropylene, acrylic resin, aramid, carbon, etc. are suitable. The diameter of the reinforcing fibers is 1 to 100 μm,
The suitable fiber length is 3 to 15 mm. This reinforcing fiber is contained in the composition in a proportion of 0.1 to 10 parts by weight based on the weight of cement OO. If the amount of reinforcing fibers is too small, the strength of the resulting molded product will decrease.

If it is in excess, the dispersibility when mixing the ingredients of the composition will be poor, resulting in a decrease in the strength of the resulting molded product.

Cellulose-based admixtures are used for the purpose of imparting a certain degree of viscosity and improving fluidity when extruding a composition. As the cellulose-based admixture, methylcellulose, hydroxyethylcellulose, etc. are preferably used. The cellulose-based admixture is contained in the composition in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of cement. If the amount is too small, the viscosity of the composition will be low, while if it is too large, the viscosity will be high, resulting in poor moldability.

In order to manufacture a cement molded body using the composition of the present invention, a process similar to conventional cement extrusion molding can be adopted. For example, first of all, the above cement, edenite, inorganic aggregate,
Tri-blend the reinforcing fibers and cellulosic admixture. An appropriate amount of water is added to this mixture for wet blending, and then thoroughly kneaded using a kneader. The obtained plastic kneaded material is introduced into an extrusion molding machine having a desired mold, and extrusion molding is performed under pressure. The extruded molded product having the desired shape is heated under predetermined conditions (for example, at a temperature of 40 to 60"C,
? Leave it for 4 to 48 hours (W degree 90 to 100%) for 4 to 48 hours (
It hardens by curing). The above 5 blending steps,
General-purpose equipment can be used for both the kneading process and the extrusion molding process.

(Function) When the above cement composition is extruded according to the present invention, in the extruder, if the water content of the kneaded product is relatively low (
For example, when obtaining a molded article with a complex irregular cross section), it has sufficient fluidity and has a uniform flow rate. Furthermore, the extruded uncured molded product has sufficient shape retention until curing progresses. These good properties are due to: ■ The inorganic aggregate in the cement composition is mainly spherical particles, which exhibit a bearing effect under pressure; and ■ The composition contains the above-mentioned inorganic aggregate and reinforcement. This is thought to be mainly due to the fact that the shape retention is sufficient after extrusion due to the presence of fibers. The extruded uncured molded product has good shape retention and does not deform before it hardens. Since the obtained cured molded body contains edenite,
The molded body has sufficient strength and impact resistance. Such molded bodies are suitably used for flooring materials, wall materials, etc. of houses.

According to the present invention, a high-strength cement molded body that can be passed through flooring and wall materials can be easily manufactured without using conventional asbestos fibers. As asbestos fibers are not used, there is no risk of cancer caused by asbestos dust during the manufacturing process or during use.

(Example) The invention will be explained below with reference to examples.

(A) Preparation of plastic kneaded product: Each component of the cement composition of the above formulation other than water was placed in a mixer (all-purpose mixer; manufactured by Sanei Seisakusho) and mixed for 3 minutes. Water was added to this, and after mixing for about 3 minutes, the mixture was sufficiently kneaded using an Ogu kneader (MP-100 type; manufactured by Miyazaki Iron Works Co., Ltd.) to obtain a plastic kneaded product.

(B)-1 Preparation of flat cement molded product; The kneaded material obtained in section (A) was processed using a vacuum extrusion molding machine (MV −
FM-A-1 (manufactured by Miyazaki Iron Works) hopper.

Width 250mm, thickness 15M, length 50mm by extrusion molding
A cm flat plate sample was prepared. The extrusion pressure and extrusion amount per unit time at this time were measured. The extrusion pressure was measured by measuring the pressure in the resistance section from the barrel of the extruder to the mold using a Bourdon tube pressure gauge. The extrusion amount per unit time was calculated by a linear equation by measuring the length (cm/m1n) of a flat sample extruded from the die tip for 60 seconds.

T: Extrusion amount per unit time (42/hr) α: Cross-sectional area of mold exit (C) β: Length of extruded flat sample (cm/min) The above uncured molded body was heated for 5 hours. After leaving it at room temperature (preliminary),
It was maintained (cured) at 50°C for 40 hours in an atmosphere of R1195% or higher.

(B) Preparation of a molded article with a -2 Ω-shaped cross section: As shown in FIG. A mold having an outer mold 12 in which a recessed groove 12a into which the upper portion fits was disposed along the longitudinal direction was prepared. The widthwise dimension of the top surface of the protrusion of this inner mold 11 is 1 cm, the widthwise dimension of the bottom surface is 9cm, and the height is 5cm. The widthwise dimension of the opening of the concave groove of the outer mold 12 is 11.5 cm, and the widthwise dimension of the inner deep part is 9.5cm.
, and the depth is 5 cm. Separately, an uncured long plate-shaped cement molded body (25CTII x 1.5 cm x 35 cm) was obtained by extrusion molding in the same manner as in Section (B)-1. This uncured long plate-shaped cement molded body 3 is shown in Figure 1 (
As shown in FIG. 1(b), each side in the width direction is placed on a pair of support plates 21 and 22 which are arranged opposite to each other with the protrusion of the inner mold 11 in between, and as shown in FIG. 1(b). As shown, the inner mold 11 and the outer mold 12
Press (pressure 10 kg/cnT, 10 seconds) with
An uncured molded body 30 having an Ω-shaped cross section as shown in FIG. 1(C) was obtained.

This uncured molded body was cured according to Section (B)-1.

As shown in FIGS. 2(a) and 2(b), a cured molded body 31 having a concave portion projecting upward was obtained.

(C)-1 Performance evaluation of molded product: The sample obtained in section (B)-1 after immersion was cut into 25 mm in length and 240 cm in length (cut perpendicular to the extrusion direction) L, 105”C. After drying in a gear oven for about 48 hours, the sample was allowed to cool to room temperature.The sample was supported at intervals of 200 mm, and the bending strength was measured by applying force to the center at a bending speed of 2.5 mm/min ( Bending strength test).Separately, the sample after curing was cut into 250 mm width and 250 mm length (cut perpendicular to the extrusion direction) and subjected to oven treatment in the same manner as above.

This sample was placed on flat river sand, and one
A steel ball weighing 1 kg was dropped from a height of 2 m, and it was observed whether any abnormalities were observed in the sample (impact strength test). The results of each test are shown in the table below.

(C)-2 Performance evaluation of molded product: The cured molded product 31 obtained in section (B)-2 was cut into a length of 30 cm perpendicular to the longitudinal direction, and the depth of the recess was (shown in (b)) was measured using a caliper. The results are shown in the table below. In the impact resistance section of the table below, ◎ indicates that no abnormalities were observed.
O indicates that a crack occurred only on the front surface, Δ indicates that a crack occurred on the back surface, and × indicates that the test piece was divided.

The results of Examples 2 and 3 and Comparative Examples 1 and 2 are also shown in the table below.

In addition, the amount of Edenite was 30 parts by weight, and the amount of water was 4 parts by weight.
The same as Example 1 except that the amount was 0 parts by weight.

The amount of Edenite was 30 parts by weight, the amount of water was 42 parts by weight, and the inorganic aggregate was silica hume (particle size 0.
The procedure was the same as in Example 1 except that 10 parts by weight (1 μm) was used.

This example is the same as Example 1 except that Edenite was not used.

Example 1 except that no reinforcing fibers were used, the amount of Edenite was 30 parts by weight, and the amount of water was 40 parts by weight.
It is similar to

(The following is a blank space) From Table 2, it can be seen that when the composition of the present invention is used, a cement molded body can be obtained with good moldability by extrusion molding. The obtained uncured molded product has excellent shape retention, and the molded product obtained by curing has excellent bending strength and impact resistance.

(Effects of the Invention) According to the present invention, a cement molded body having high strength and excellent impact resistance can be obtained by extrusion molding with good moldability and high efficiency. Such a cement molded body is suitably used as, for example, a flooring material such as a decking material for an apartment complex or a hallway material, or a wall material.

Since it does not contain asbestos, there is no risk of cancer caused by asbestos dust either during the manufacturing process or during use.

4. Figures 1 (a) to (C) are explanatory diagrams showing an example of the process of press working an uncured long plate-shaped cement molded body obtained by extrusion using the present invention, and FIGS. 2(a) and 2(b) are a perspective view and a cross-sectional view of a cement molded body having an Ω-shaped cross section obtained by the press working.

3... Uncured long plate-shaped cement molded body, 30... Ω-shaped cross section cement molded body.

Claims (1)

[Claims] 1. Edenite is 2 to 100 parts by weight of cement.
50 parts by weight, 10 to 100 parts by weight of inorganic aggregate, 0.1 to 10 parts by weight of reinforcing fibers, and 0 parts by weight of cellulose admixture.
．． A cement composition containing 1 to 10 parts by weight.