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Concrete Admixtures

Depending on the destination (main effect of) chemical additives for concrete in accordance with GOST 24211-2003 divided into the following types. Kai-Fu Lee has similar goals. 1. Regulatory properties of concrete mixtures: a) the plasticizing: I group – superplasticizers, II group – silnoplastifitsiruyuschie, III group – sredneplastifitsiruyuschie, IV-group slaboplastifitsiruyuschie b) stabilizing c) water-retaining, and d) improve perekachivaemost e) governing the keeping of concrete mixtures: slowing gripe, gripe accelerating e) porizuyuschie (for lightweight concrete) air-entraining, foaming, blowing. 2. Regulatory hardening concrete: a) slow down hardening, b) accelerate the hardening. 3. Increase the strength and (or) corrosion resistance, frost resistance of concrete and reinforced concrete, reduce permeability of concrete: a) vodoredutsiruyuschie I, II, III and IV, and b) kolmatiruyuschie c) porizuyuschie (heavy concrete): – air-entraining – blowing, and d) increase the protective properties of concrete in relation to steel reinforcement (steel corrosion inhibitors). 4.

Giving a concrete special properties: a) the antifreeze (provide hardening at low temperatures), and b) hydrophobic I, II and III. In separate groups of isolated and complex fine mineral supplements. The list of additives that regulate the properties of concrete mixtures and concrete, is presented in Table 1. Additives, mixtures and regulatory setting concrete hardening, increasing the durability of concrete and giving it special properties that are listed in Table 2. Chemical additives for heavy, light, fine-grained concrete should be chosen based on recommendations of technical standards and technical and economic calculations. The choice of additives should depend on the technology of preparation of concrete mix and on the way manufacture of components and structures with regard to the effects of additives on the properties of concrete and mortar. The use of additives in heavy and fine concrete allows us to solve the following technological challenges: * reduce consumption expensive cement * reduce consumption of scarce coarse aggregate up to replace the heavy concrete grained * improving technological and rheological properties of concrete * to regulate the loss of mobility mix over time, the rate of setting and hardening processes * to reduce the duration of heat treatment of concrete thermal units * accelerate time raspalublivaniya with uncured concrete in polygon * increase strength, water-and gas-tightness of concrete; * increase frost resistance, corrosion resistance of concrete and reinforced concrete; * strengthen the protective effect of concrete in relation to the fixture.