JPH0549621B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides latent hydraulic substances, reactive siliceous substances, alkali metal hydroxides, cement water reducing agents,
and a chemically resistant and heat resistant binder containing a polymer. Conventionally, acid-resistant cements include water glass, alumina cement, and blast furnace cement. Portland cements have no resistance to acidic substances, so they cannot be applied to areas that require acid resistance, and even if they are forced to do so, they must be repaired frequently. Water glass-based products have low alkali resistance and water resistance, alumina cement-based products are not effective depending on the type of acid, and blast-furnace cement-based products also contain a considerable amount of portland cement, so they do not have high acid resistance. . For this reason, attempts have been made to improve the chemical resistance by adding alumina cement or fly ash to water glass, but it has not yet been achieved (Special Publication No. 47-32811). By adding alkali stimulants such as Ca(OH) ₂ and Na ₂ CO ₃ to the potential hydraulic substances of furnace slag and fly ash, the hydraulic properties are increased, and when mixed with water, it hardens, although more slowly than in the case of Portland cement. , is known to cause coagulation and hardening. The present inventors attempted to obtain an acid-resistant and heat-resistant binder using a latent hydraulic substance, but the acid resistance and heat resistance were insufficient simply by adding an alkaline irritant. Therefore, a reactive siliceous material was used, but although the acid resistance was improved in this case, the compressive strength was significantly lowered. However, when alkali metal hydroxide and cement water reducing agent are added to the reactive siliceous material, both acid resistance and heat resistance are improved.
Improved workability and no decrease in compressive strength.
Furthermore, the inventors discovered that the adhesion and fluidity can be improved by using a polymer in combination, leading to the completion of the present invention. Latent hydraulic substances used in the present invention include steel slag, fly ash, etc. Steel slag includes blast furnace slag and converter slag, and blast furnace slag includes granulated slag with high latent hydraulic properties and slowly cooled slag with low latent hydraulic properties. . Granulated slag is suitable for the present invention, and the vitrification rate is preferably 50% or more and the basicity = CaO + MgO + Al ₂ O ₃ /SiO ₂ 1.5 or more. To increase chemical resistance
Although it is desirable to reduce the CaO component as much as possible, strength development tends to decrease. In the present invention, by using a reactive siliceous material and an alkali metal hydroxide, an alkali-silicate reaction occurs and a silicate gel is produced. This silicic acid gel not only has excellent acid resistance, but also generates swelling pressure by taking in free water, which has the effect of reducing drying shrinkage and making the tissue denser, thereby suppressing acid penetration. The powder degree of the latent hydraulic substance is 2000 cm ² /g or more in Blaine specific surface area. If it is less than 2000 cm ² /g, strength development is not sufficient. Moreover, when the amount exceeds 8000 cm ² /g, the effect almost reaches its upper limit, and the crushing power increases, making it uneconomical. The alkali metal hydroxides according to the present invention act as alkaline stimulants for latent hydraulic substances, and include hydroxides of lithium, sodium and potassium. Industrially, sodium hydroxide is common. Furthermore, an alkali metal carbonate may be used in combination. Reactive siliceous substances include so-called activated silica, opal, silica flower, colloidal silica, diatomaceous earth, Aerosil, silica gel, glassy No. 1, 2, 3, and 4 sodium silicate, crystalline sodium metasilicate, ortho There are sodium silicate, sodium pyrosilicate, etc., but the composition of sodium silicate type is Na ₂ O/
SiO ₂ =0.1 to 5.0, preferably 0.2 to 1.1 (molar ratio). When sodium metasilicate is used in combination with an alkali stimulant as in the present invention, not only acid resistance and heat resistance but also high strength can be obtained, but there is no particular outstanding initial strength. However, the strength increase after 1 to 2 months is remarkable, and it can be said to be a particularly preferable reactive siliceous material. These may be used in the form of powder or solution, and the amount added is 30 to 60 parts by weight, preferably 40 to 50 parts by weight, of the reactive siliceous material per 100 parts by weight of the latent hydraulic substance. be. The amount of the alkali metal hydroxide is 1 to 30 parts by weight, preferably 3 to 15 parts by weight. If the amount used is other than this, the desired effect will not be obtained. In the present invention, generally commercially available cement water reducing agents can be used as cement water reducing agents, but in particular compounds having a sulfone group in the molecule,
For example, akylaryl sulfonate series, aromatic polycyclic condensate sulfonate series (trade name "Mighty",
"Pozolith", "Melment"), oxyorganic acid salts, and saccharides are preferred. By selecting one or more of these and using them in combination, acid resistance, heat resistance, and bending strength can be significantly increased.
The amount added is 0.1 per 100 parts by weight of the potential hydraulic substance.
The amount is about 6.0 parts by weight, preferably 0.2 to 4.0 parts by weight. The disadvantages of slag cement are lack of strength,
It has been pointed out that the surface hardness is low, the drying shrinkage is large, and the strength decreases over a long period of time, and the use of the above-mentioned cement water reducing agent is effective to improve these problems. Furthermore, in the present invention, a polymer is used in combination not only to improve acid resistance but also to improve adhesive strength and fluidity. For example, natural rubber (NR), chloroprene rubber (CR), styrene butadiene rubber (SBR),
Rubber latex such as acrylonitrile butadiene rubber (NBR), epoxy, vinyl chloride, vinylidene chloride, vinyl acetate, ethylene-vinyl acetate copolymer, asphalt, resin emulsion such as rubber asphalt, casein, cellulose derivatives, ethylene glycol-propylene glycol copolymer Examples include water-soluble polymers such as polymers, vinyl alcohol, acrylates, furfuryl alcohol, and acrylamide, and powders of these may also be added. When these polymers are used in combination, not only acid resistance but also adhesive strength, bending strength, and fluidity are improved. The binder of the present invention can be used in all applications where Portland cement is normally used, such as structures that require acid resistance and secondary concrete products. In addition, acid resistance can be imparted by lining the surface of structures or secondary concrete products such as humid pipes, piles, and poles, which are normally made with Portland cement. Also,
It has significantly better heat resistance than ordinary Portland cement, so it can be used as a binding material for acid-resistant castables. Furthermore, it has excellent adhesion, alkali resistance, water resistance, and fluidity, so it can be used as a floor finishing material, that is, a self-leveling material, especially in areas where chemicals, food, etc. are handled. . The present invention will be specifically explained below with reference to Examples. Reference Example 1 A binder was prepared using the formulation shown in Table-1.
Sand and water were added to this binder and kneaded to prepare a specimen, which was tested for strength development, acid resistance, alkali resistance, and water resistance. The results are also listed in Table-1. In addition, the specimen was made with a cement/sand ratio of 1:2 and a water/sand ratio of 1:2.
The cement ratio was 40%, and 4 x 4 x 16 cm pieces were made and air-dried at 20°C and 80% RH. In addition, the flow value and compressive strength were measured according to JIS R5210. Acid resistance, alkali resistance, and water resistance were determined by air-drying for 7 days, immersing in each solution for 28 days, and then taking them out and measuring their weight to determine the rate of change. <Materials used> Latent hydraulic substance α: Granulated blast furnace slag, fineness 5120
cm ² /g, basicity 1.87, vitrification rate 90% 〃 β: Fly-ash alkali stimulant A: Sodium hydroxide 〃 B: Sodium carbonate Reactive silica-containing substance a: Opal, 1 mm or less 〃 b: Sodium metasilicate,
1mm or less 〃 c: No. 3 sodium silicate,
Cement water reducing agent of 1 mm or less A: Sodium lignin sulfonate B: Dextrin C: Sodium gluconate As shown in Table 1, the binder of the present invention has practically no problem in strength development and well-balanced chemical resistance. It is something that has a nature.

[Table] The particle size of the reactive siliceous material used was 1 mm or less.

[Table] In the table, all numbers other than experiment No. and composition No. are compressive strength values.
(Kgf/ ^cm2 )
Example 1 SBR latex was added to each formulation shown in Table 1.
An acid resistance test was conducted in the same manner as in Reference Example 1 except that 10 parts by weight was added. As a result, the weight loss rate was reduced by 10 to 20% compared to each experiment of Reference Example 1. Reference Example 2 A mortar specimen measuring 4 x 4 x 16 cm was prepared using the same formulation as in Reference Example 1, and a heat resistance test was conducted. After the specimens were air-dried for 7 days, they were cured for 3 days at each temperature shown in Table 2.
heated for an hour. After heating and cooling, the compressive strength was measured. Incidentally, in this example, the aggregate used was Shamotsu grains. As shown in Table 2, the binder of the present invention
It has excellent heat resistance without any significant decrease in strength.

[Table] Reference Example 3 The relationship between the amount of cement water reducer added and acid resistance was investigated. Experimental conditions similar to those in Reference Example 1 were applied using sodium lignin sulfonate to the formulation of Experiment No. 1-17 shown in Table 1, and 2.0 and 4.0 parts by weight of dextrin to the formulation of Experiment No. 1-18, respectively. When the acid resistance was investigated, the dextrin type showed a clearer effect of improving acid resistance than the sodium glininsulfonate type. Example 2 Latent hydraulic substance α 100 parts by weight, alkaline stimulant
5.0 parts by weight of A, 2.5 parts by weight of B, cement water reducer
The same procedure as Reference Example 1 and Reference Example 2 was carried out except that 0.5 part by weight, 0.1 part by weight, and the formulation shown in Table 4 were used. <Materials used> Polymer: Denki Kagaku Kogyo Co., Ltd. product name "Denka"
EVA Tex #83” solid content 55%, ethylene/
Vinyl acetate = 20/80, glass transition temperature 0°C 〃: Product name “Ultrasol CWX-43” manufactured by Takeda Pharmaceutical Co., Ltd. Solid content 45%, acrylic acid ester copolymer emulsion 〃: Product name “NipoL” manufactured by Nippon Zeon Co., Ltd.
LX206” solid content 45%, styrene-butadiene latex 〃: Denka Kagaku Kogyo Co., Ltd. product name “Denka Chloroprene Latex LK-50” solid content 50%,
polychloroprene

【table】

Claims (1)

[Claims] 1 100 parts by weight of a latent hydraulic substance with a Blaine specific surface area of 2000 cm ² /g or more, 30 to 60 parts by weight of a reactive siliceous substance
1 to 30 parts by weight of an alkali metal hydroxide, 0.1 to 6.0 parts by weight of a cement water reducer, and a chemically resistant, heat-resistant binder containing a polymer.