ENSURING CARBONIZATION RESISTANCE OF AUTOCLAVE HARDENED CONCRETE CONCRETE

Abstract

he analysis of tendencies of production of autoclaved aerated concrete is resulted. Given the price factor, energy and environmental status of the industry of construction wall and insulation materials, autoclaved aerated concrete has significant advantages over traditional wall materials and prospects for production.

Studies of the durability of autoclaved aerated concrete are due to the increase in its production and use in the construction industry in recent years due to rising energy costs and the need to reduce greenhouse gas emissions. At the same time, the density of aerated concrete decreased almost 2 times.

 The transition to the production of low-density autoclaved aerated concrete D300, D150 on the one hand improves the thermophysical characteristics of aerated concrete, reduces material consumption, on the other - increases the specific cost of binder (cement) per unit mass of aerated concrete and increases its vapor and air permeability. High vapor permeability and adsorption properties of water vapor and gases from the air pose a potential threat due to possible carbonization of aerated concrete, "loosening" of the macrostructure of the material during wetting and drying, irreversible deformation during freezing and thawing of wet aerated concrete, which occur almost simultaneously. Under the conditions of soaking, capillary suction of water and adsorption of water vapor, the processes of carbonization of autoclaved aerated concrete are accelerated.

The material can adsorb moisture and carbon dioxide from the air. The formation of carbon dioxide in aerated concrete reduces the alkaline environment, neutralizes free lime and the destruction of calcium hydrosilicates and corrosion of reinforced products.

Carbonization can have both positive and negative effects on cement concrete. To ensure the carbonization stability of autoclaved aerated concrete should be achieved by implementing a number of technological solutions that increase the carbonization resistance of autoclaved aerated concrete while reducing the clinker component in the mineral binder. The results of the use of natural mineral additives of hydraulic and pozzolanic action in the composition of autoclaved aerated concrete are given.