North of China is located in cold zone

therefore

action of low temperature and freeze-thaw cycle become the main reason of deterioration of concrete performance.The stress-strain curve of concrete under freeze-thaw cyclic action is very important because the uniaxial compression stress-strain relationship of concrete reflects its basic mechanical performance.Based on grey theory and the existing stress-strain parametes of frozen-thawed concrete tested by uniaxial compression

predictive equations were established to predict the stress-strain parametes of concrete with other different freeze-thaw number.Then

according to the constitutive curve of concrete suggested by Guozhenhai

a series of stress-strain curves of concrete with different freeze-thaw numbers were fitted.The results show that the fitted stress-strain curves of freeze-thaw concrete by constitutive parameters predicted based on grey theory are in agreement with experimental ones.So this method can be used to study the stress-strain full curves of concrete with any freeze-thaw number in the range of relevant experiments.