On the Deteriorative Indexes of Concrete subjected to Rapid Freezing and Thawing

摘要

Many methods are being used to determine the resistance of concrete specimens to rapidly repeated cycles of freezing and thawing in the laboratory. The relative dynamic modulus of elasticity in frequency method among the rest is widely used to measure the degree of deterioration of concrete specimens、for a good correlation can be seen　between values of the dynamic modulus of elasticity change and the strength change of concrete. On the other hand, some faults of this method have already been pointed out.　　　In this paper, various measuring methods are used to estimate the degree of deterioration of concrete. They are relative dynamic modulus of elasticity in ultrasonic method, in addition to frequency method, length change in dialgage and contact gage method, and weight change. From the test results, it can be concluded that length change in dialgage method expresses clearly the degree of deterioration and has a good parallel relation to dynamic modulus of elasticity