METHOD OF TESTING CONSTRUCTION MATERIALS FOR FROST RESISTANCE Russian patent published in 1996 - IPC

FIELD: construction industry. SUBSTANCE: samples are prepared in agreement with method. They are saturated with water, then are frozen and thawed. In process of freezing samples are subjected to action of variable pressure of air or water medium. Temperature is measured on surface and at point of sample most distant from surface. Pressure in process of freezing is increased if value of temperature on surface of sample is less than temperature inside sample. Samples in process of thawing are exposed to vacuum if temperatures inside and on surface of sample are equal to obtain pressure not exceeding 80% of starting pressure of air or gas atmosphere. EFFECT: improved reliability of method. 2 cl