JPS6146434B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a waterproofing agent suitable for coating on cement mortar or concrete. A variety of waterproofing agents have been proposed to be applied to cement mortar and concrete, but some of these waterproofing agents give waterproofness by being kneaded into the concrete at the same time as the construction. It is divided into two types: those that add waterproofness by applying it to the surface afterwards. Of these, in the former case, chemicals such as water-repellent substances and polymers are used, but these additives are expensive, which not only increases the cost of the waterproofing agent, but also increases the cost of the cement. Since it is mixed in during kneading, there are problems such as having an adverse effect on the hardening phenomenon of cement. On the other hand, in the latter case, although it has little effect on the cement hardening phenomenon, it not only has problems such as poor adhesion to the construction surface and surface deterioration, but also requires expensive additives. There were problems such as the necessity of using . As a result of intensive research to improve waterproofing agents that belong to the latter category, the present inventors have found that they not only eliminate the drawbacks associated with the conventional methods described above, but also have waterproofing properties that are superior to conventional waterproofing agents. We have discovered a new agent and achieved the present invention. The present invention will be explained in detail below. The waterproofing agent of the present invention is made by combining 100 parts by weight of an inorganic cement-based material and an amorphous silicic acid material such as cheap plate glass or scrap glass discarded as waste so that the powder degree is 7,000 to 10,000 cm ² /g. It consists of 10 to 20 parts by weight of a finely pulverized product obtained by finely pulverizing the powder, and 0.1 part by weight or less of an anionic surfactant to provide a dispersion effect and a penetration effect, which is added as necessary. As the inorganic cement material, for example, ordinary Portland cement, early strength Portland cement, and other known cements are used. Further, as the finely pulverized material of the amorphous silicic acid material, plate glass, scrap glass, etc. can be used with a powder degree of 7000 to 7000.
It is used after being pulverized to 10,000 cm ² /g. When the fineness of the amorphous silicic acid material is less than 7000 cm ² /g, the activity of the finely ground material decreases, and the reactivity decreases.
Performance deteriorates. On the other hand, if it is larger than 10,000 cm ² /g, particles will aggregate during the grinding process, resulting in poor performance. In addition, the amount of the finely pulverized amorphous silicic acid material mixed is 100% of the inorganic cement-based material.
If the amount is less than 10 parts by weight, the amount of reaction due to dissolution of the amorphous silicic acid substance will be small, and the waterproofing effect will be low. On the other hand, if the amount is more than 20 parts by weight, the strength of the waterproofing agent itself decreases, resulting in poor durability under severe conditions such as under high water pressure, and also poor adhesion to the coated surface. Further, as the anionic surfactant, sodium alkylnaphthalene sulfonate or the like is used. The amount may be small as long as it can lower the surface tension when kneaded with water and provide a dispersion effect and a penetration effect, for example, 0.1 part by weight or less per 100 parts by weight of the inorganic cement material. Therefore, when using the waterproofing agent of the present invention having the above composition, for example, a method of adding water to the waterproofing agent, kneading it, and applying it to the surface of a cured product, etc.
A method of spraying and applying the present waterproofing agent directly onto the surface of a wet cured product can be applied. In addition, in the latter method of spraying powder, it is desirable to perform a process of pressing the powder onto the coated surface with a trowel or the like after spraying. As explained above, the waterproofing agent of the present invention contains 100 parts by weight of an inorganic cement-based material and a fineness of 7,000 to 7,000 parts by weight.
Finely ground amorphous silicic acid material with a density of 10000cm ² /g
It is composed of 10 to 20 parts by weight and 0.1 part by weight or less of an anionic surfactant, which may be added as necessary. When the waterproofing agent of the present invention is applied to cement mortar or concrete, good waterproofing properties can be obtained, and the mechanism thereof is thought to be as follows. That is, although sheet glass and the like are generally said to be chemically stable, finely pulverized materials have a large surface area and therefore have high activity due to the behavior of surface silanol groups. Therefore, it reacts with a strong alkaline solution produced when an inorganic cement material and water are mixed, and the alkali components and silicic acid components in the amorphous silicic acid material are easily eluted. This eluted component penetrates into the interior of the hardened cement body through the pores and reacts with hydrates, particularly calcium hydroxide, etc. in the hardened cement body to produce a gel-like or crystalline substance. These products fill the fine voids in the cured product and develop resistance to water penetration. Furthermore, since the glass particles are also fine, it is thought that the action of filling the capillary voids and the like by these particles acts as a synergistic effect, thereby imparting waterproof properties. In particular, when an anionic surfactant is blended, a dispersion effect and a permeation effect are exhibited, so that the above-mentioned effects are favorably exerted, and very good waterproof properties can be obtained. In addition, anionic surfactants improve the fluidity of the waterproofing agent paste and also form a dense film on the surface of the cured product, making it easier to apply and producing a good waterproofing film. The effects of the present invention will be listed below. (1) Because plate glass and scrap glass are used,
The waterproofing agent can be produced at a very low cost, and if waste glass is used, it is also effective in terms of resource reuse. (2) Since it penetrates into the hardened cement and forms a waterproof layer, a semi-permanent waterproofing effect is obtained and no problems such as surface deterioration occur. (3) As described in the previous section (2), since the cured product and the applied part form a mutual structure, the adhesiveness with the construction surface is good and surface peeling does not occur. (4) The construction method is simple and the construction cost is low. (5) It has a significantly lower water permeability than conventional waterproofing agents, and has very good waterproof properties. Hereinafter, the present invention will be specifically explained with reference to Examples. [Example] After pulverizing plate glass, it was mixed with ordinary Portland cement to form a waterproofing agent. Next, a mixture of 40 parts by weight of water and 0.05 parts by weight of sodium alkylnaphthalene sulfonate was mixed and kneaded per 100 parts by weight of this waterproofing agent to prepare a kneaded product of the waterproofing agent. The kneaded product of this waterproofing agent is JIS-A-1401-
1.5 kg/m ² (0.5 mm thickness) was applied to the surface of a 7-day old 1:3 mortar prepared in accordance with 1977. After curing in humid air for 3 days, it was cured in a curing box with 80% humidity for 15 days, and then tested in a water permeability tester at a water pressure of 3.
Tested in Kg/ ^cm2 . (a) Relationship with glass powder fineness The Blaine value of glass powder fineness is 5100, 7400,
The water permeability was measured by changing it to 9700 and 12000 cm ² /g. The mixing ratio of glass powder was 20 parts by weight per 100 parts by weight of ordinary Portland cement. The results obtained are shown in Table 1 below.

[Table] As is clear from Table 1 above, good effects can be obtained when the fineness of the glass powder is within a predetermined range. (b) Relationship with the amount of glass powder mixed
The water permeability was measured by changing the amount to 5, 10, 20, 40, and 60 parts by weight per 100 parts by weight. In addition, the fineness of the glass powder was all set to 9700 cm ² /g in Blaine value. The results obtained are shown in Table 2 below.

【table】

[Table] As is clear from Table 2 above, the amount of glass powder mixed per 100 parts by weight of ordinary Portland cement
Good effects can be obtained within the range of 10 to 20 parts by weight. (c) Results with optimum fineness and mixing amount The waterproofing agent was adjusted by setting the fineness of glass powder to 9700 cm ² /g and the mixed amount of glass powder to 10 and 20 parts by weight, respectively, per 100 parts by weight of ordinary Portland cement (respectively). (referred to as waterproofing agent A and waterproofing agent B).
These waterproofing agents A and B were applied to 1:3 mortar, and the water permeability and water permeability ratio were measured at 1 hour, 5 hours, 8 hours, and 19 hours. The results obtained are shown in Table 3 below. In addition, for comparison, similar water permeability tests were conducted on a commercially available product coated with the currently most proven waterproofing agent according to its specifications, and an uncoated product with no waterproofing agent applied. The results are shown in Table 3 below. The commercially available product consists of powdered water glass, cement, soda ash, organic surfactant, and silica sand.

[Table] As is clear from Table 3 above, waterproofing agents A and B of the present invention have better waterproofing properties than uncoated products as well as commercially available products.

Claims (1)

[Claims] 1. 100 parts by weight of an inorganic cement-based material and
A waterproofing agent for an inorganic hydraulic substance, characterized in that it contains 10 to 20 parts by weight of a finely pulverized amorphous silicic acid substance such as plate glass or scrap glass having a particle size of 7,000 to 10,000 cm ² /g. 2. The waterproofing agent according to claim 1, which contains 0.1 part by weight or less of an anionic surfactant per 100 parts by weight of the inorganic cement material.