Fuzzy Analysis Of Time-variant Reliability Of Concrete Structures Under Freezing-thawing Alternative Action

Nowadays damage caused by freezing-thawing leads to deterioration of structures in advance, especially in hydraulic concrete. In this paper, fuzzy mathematics is intreoduced into the reliability analysis of concrete freezing-thawing. Researches on freeze-resistance of concrete structures are conducted.According to the analyses of the mechanism of concrete freezing-thawing and failure criterion, the freezing-thawing damage of concrete is an accumulation of damage. There isn't a definite limit between safety and failure of concrete structures. With the increasing times of freezing-thawing circle, resistance of concrete is decreasing. Considering the difference in temperature, a fuzzy time-depdendent reliability model of freezing-thawing damage of concrete is proposed by useing the method of fuzzy mathematics. This model reflects the real environmental effect on concret freezing-thawing, considering the time-variant resistance, the fuzzy property of concrete freezing-thawing and the influence of temperature difference. The results demonstrate that the fuzzy time-depdendent reliability model of freezing-thawing damage of concrete has good agreement with the real reliability.