JPS6150915B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a lime silicate cement product, which has appropriate lightness and excellent strength.
The present invention aims to provide an accurate manufacturing method for a new cement product that has excellent properties such as high water resistance, low water absorption, and chemical resistance, and is suitable for use as an external structural material. Paste, mortar, or concrete using lime silicate cement is widely used in civil engineering construction today, and various technologies have been proposed to reduce the weight of such products. In the field, it is essential for materials such as insulation, fireproofing, and heat retention, curtain walls in high-rise buildings, PC boards, and fireproof coatings. However, in the conventional method of obtaining such lightweight concrete products using foaming agents or reactive foaming agents, the bubbles formed in the concrete structure are relatively large in diameter. Even if it is possible to achieve a certain degree of light weight, the product strength is inferior,
It has the disadvantage of high water absorption, poor water absorption, and poor chemical resistance. The present invention was created through repeated research in view of the above-mentioned circumstances, and is a new product that has excellent strength, low water absorption, and excellent water and chemical resistance while ensuring appropriate lightness. We have succeeded in obtaining the above cement product and a preferable method for producing the same. That is, in the present invention, bubbles of 5 to 40 microns, with an average bubble size of about 30 to 10 microns, are dispersed and formed in a lime silicate cement structure. The purpose of the kneading process is to use sodium alpha eulene sulfonate and sodium paraffin sulfonate in combination. In other words, to explain the present invention, foaming agents that have been conventionally employed for the purpose of reducing the weight of cement products as described above include proteinaceous foaming agents such as albumin and casein, and surfactants such as ABS. There are many kinds of materials, mainly those of the same type, and these materials can form bubbles and achieve the purpose of weight reduction. However, in these conventional products, the diameter of the bubbles formed is relatively large, with an average diameter of 60μ or more, and the bubbles formed during kneading lack stability.
Particularly in the case of heated kneading using hot water or steam, which is used to increase the productivity of secondary concrete products such as PC plates,
It is normal for the foamability to deteriorate by more than 30% under temperature conditions of ℃ or higher, and even if fine bubbles are formed during kneading, their disappearance and the coalescence of adjacent bubbles to form a large size are unavoidable. Favorable strength properties etc. cannot be obtained. The present invention provides a cement product in which fine bubbles with an average particle size of 20 μm or less are uniformly dispersed, and for this purpose, sodium alpha eulene sulfonate { : However, m + n = average 11, p + q = average 11} (hereinafter
It is proposed that sodium paraffin sulfonate be added to this SAOS at a ratio of 5:1 to 1:1 (weight ratio). The SAOS described above has a molecular structure with few double bonds, has good stability because it is a sodium sulfonate salt, and has excellent chemical resistance such as alkali resistance. The cement content of each kneaded product with aggregate added to
When 0.005 to 0.05% by weight is added, extremely fine bubbles are formed, and the foaming effect is good, stable bubbles are formed, and there is no large bubble formation or disappearance due to aggregation of bubbles, and it can be heated and kneaded at 30℃ or higher. Even when the molded product is cured, preferable cell formation is ensured, and a product member with small drying shrinkage after curing of the molded product, excellent water resistance, and excellent strength can be obtained. In addition, when sodium paraffinsulfonate having a carbon number of 11 to 12 is mixed with this SAOS at a ratio of 5:1 to 1:1, the sodium paraffinsulfonate whose lipophilic group is paraffin is used as a base for silicate lime cement. It has been confirmed that waterproof properties can be imparted to the bubble surface of the hardened structure after hydration hardening, and that its properties can be further improved and materials such as exterior wall materials can be manufactured appropriately. As mentioned above, the number of carbon atoms in the paraffin part is preferably about 11 to 12 from the viewpoint of the melting point.If the blending ratio is less than 5:1, the effect cannot be effectively obtained, and if it is more than 1:1, the bubble size will be reduced. There is a tendency for the bubbles to become larger, and the stability of the formed bubbles may be lost. Specific embodiments of the present invention will be described below. Example 1 Water was added to ordinary Portland cement and kneaded for 3 minutes using an asphalt mixer to obtain a cement paste, and the amounts of SAOS and sodium paraffin sulfonate were varied in various amounts to determine the mixing relationship and the kneaded state. The compressive strengths of the molded bodies thus obtained are shown in Table 1 below.

【table】

[Table] Example 2 Properties of various mortars using ordinary Portland cement and Toyoura standard sand, water added thereto, and an asphalt mixer using the present invention and conventional protein-based foaming agents, and the properties obtained thereby The results of measuring the strength and water absorption of the molded bodies are shown in Table 2 below.

【table】

[Table] Also, 2-1 to 2-5 and 2 shown in this Table 2
The results of measuring the drying shrinkage rate of each of the molded articles Nos. -10 to 2-14 are shown in Table 3 below.

[Table] In other words, the products 2-10 to 2-11 according to the present invention have fine bubbles in their kneaded unit weight, and have significantly reduced water absorption and drying shrinkage, and have excellent water resistance. I learned that it is. Example 3 Using ordinary Portland cement and lightweight aggregates (coarse aggregate and fine aggregate), kneaded materials were prepared using the present invention and a conventional protein-based foaming agent. That is, the formulation is as shown in Table 4 below. Further, the kneaded properties of this kneaded product and the strength, water absorption and drying shrinkage of the molded products obtained therefrom are as shown in Table 5 below.

【table】

[Table] That is, it was confirmed that the product according to the present invention was lightweight, had a low water absorption rate, and had excellent water resistance. According to the present invention as described above, it is possible to provide lightweight concrete having a stable and fine cell structure, that is, various concrete products having appropriate lightness, excellent strength, low water absorption, and excellent water resistance. This invention is industrially very effective because it allows for accurate production of.

Claims (1)

[Claims] 1. A silicic acid product characterized by adding and kneading sodium paraffin sulfonate together with sodium alpha eulene sulfonate when preparing paste, mortar, or ready-mixed concrete of silicate lime-based cement, and molding the kneaded product. Method for manufacturing lime-based cement products.