Autoclaved aerated concrete with high crack resistance and low water absorption and preparation method thereof

Abstract

The invention discloses autoclaved aerated concrete with high crack resistance and low water absorption. The autoclaved aerated concrete is prepared from the following raw materials in parts by weight: 40 to 60 parts of quartz sand, 15 to 30 parts of superfine sand, 10 to 20 parts of lime, 2 to 5 parts of gypsum, 10 to 15 parts of cement, 0.1 to 0.2 part of aluminum powder, 1 to 1.5 parts of fiber, 3 to 8 parts of vinyl versatate polymer emulsion with a core-shell structure, 0.5 to 1 part of nano silicon dioxide, 1 to 2 parts of calcium stearate and water, wherein the ratio of water to materials is 0.5-0.6. The concrete has high compressive bearing capacity, external constraint tensile stress, impact load action and temperature material strain, and has good mechanical strength, frost resistance and crack resistance in severe environments such as freeze-thaw resistance and the like; furthermore, the autoclaved aerated concrete prepared by the invention or the autoclaved aerated concreteprepared by the invention has relatively low water absorption and relatively high alkali resistance; the coating has excellent optical performance, water resistance and self-cleaning performance.

Description

technical field [0001] The invention relates to the technical field of concrete production, in particular to an autoclaved aerated concrete with high crack resistance and low water absorption and a preparation method thereof. Background technique [0002] Autoclaved air-entrained concrete (abbreviation: ALC) is widely used in interior and exterior partition wall materials due to its porous characteristics, which endow the material with properties such as light weight, heat preservation, heat insulation, sound insulation and fire resistance. The study found that the internal porosity of ALC reached 80%, and the water absorption rate was high. On the one hand, the migration of water in the concrete void would cause a strong interaction between water, water vapor and the pore structure, resulting in air-entrained concrete. The volume deformation coefficient of the block is too large, and there is a risk of shrinkage and cracking; on the other hand, after the internal pores of t...

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Problems solved by technology

The study found that the internal porosity of ALC reached 80%, and the water absorption rate was high. On the one hand, the migration of water in the concrete void would cause a strong interaction between water, water vapor and the pore structure, resulting in air-entrained concrete. The volume deformation coefficient of the block is too large, and there is a risk of shrinkage and cracking; on the other hand, after the internal pores of the air-entrained concrete absorb water, the apparent density, thermal conductivity, sound absorption coefficient, and seismic coefficient of the material will be seriously reduced, affecting its performance. service life

[0003] At the same time, with the standard design of building energy conservation and the improvement of people's requirements for the living environment (especially in terms of sound insulation and thermal insulation), researchers will improve the thermal insulation and sound insulation performance of ALC by increasing the pores. Strength is a mutually restrictive and unified performance of opposites. Improving the thermal insulation performance of aerated concrete by increasing pores often requires sacrificing strength; at the same time, porous aerated concrete has low impact resistance and elastic modulus, and it is difficult to achieve the performance of calcium silicate board and gypsum. The mechanical strength of light wall materials such as ceramsite board and ceramsite board, especially in the case of external damage or in harsh environments such as frequent high and low temperature, humidity exchange, etc., its resistance life will be significantly reduced

[0004] Therefore, those skilled in the art aim at the problems of excessive water absorption, low toughness and poor mechanical properties of traditional autoclaved aerated concrete, and devote themselves to developing a kind of autoclaved aerated concrete with high crack resistance and low water absorption and its preparation method

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