Assessment of Light Concrete Frost Resistance

Abstract

Abstract Heat-insulating and structural-heat-insulating light concretes used in external enclosing structures significantly reduce the heat loss of a building in the cold season. The paper solves the problem of establishing criteria for evaluating the external walls made of light concrete blocks resistance to alternate freezing and thawing in laboratory conditions. A method for studying the frost resistance of masonry made of polystyrene concrete and cellular concrete of autoclave hardening during cycles of unilateral humidification-freezing-warming of wall fragments is proposed, which is closest to the actual operating conditions. Physical, mechanical and thermophysical characteristics of heat-insulating and structural concrete are obtained. The dependences of heat-protective qualities on the degree of moisture content of the material, as well as the strength of the thawing conditions of samples in water and air conditions are established. As the normalized parameters for assessing the frost resistance of light concrete masonry by unilateral freezing it is proposed to use the adhesion strength of blocks with plaster mortar, the strength of chemical anchors (breaking methods), as well as the passage speed of an ultrasonic impulse through the masonry thickness (non-breaking method). Based on the research results, recommendations for their implementation in regulatory documents are formulated.