This paper analyzes mechanism of concrete early frost damage,discusses its expression and its permissible critical strength,and introduces application of the critical strength combined with practical engineering.

As a result, the critical strength can not be decided by it.

In this paper, transportation demand is forecasted with characteristic variables about the intensity of freight transport and per capita going number.

This paper aims to research the strength development and the resistant freezing critical strength of concrete with mineral admixture under low-temperature,and ascertain the replacement ratio of cement.

In order to find out the effects of admixture on the resistant freezing critical strength of concrete under low-temperature,the once-through artificial freezing and repetitious natural freezing methods are used to compare with concrete mixed with traditional antifreeze.

The critical aerating flux for liquid loop and critical aerating flux for fluidization of granular sludge are two important parameters for its operation.

Application the reliability design theory and methods basis on random-fuzzy probability model,it is quantitative analyzed that reliability range of virgin critical strength in buckling of cylinder during pressure test and normal operation.

The researching results show that: DFor the fuzzy reliability range of critical strength in buckling for steel thinness wall cylinder, the range should be 0.