This paper describes the influence of raw material, water-cement ratio, sand ratio, cement-sand ratio and fly ash content on impermeability of waterproof concrete. The value ranges of several important mix parameters are summarized, that provides the reference to select the parameters of mix proportion of waterproof concrete for subway.

The crack resistance evaluation indexes of concrete were chosen, which were used to study the influence of ultra-fine fly ash on the crack resistance of pavement concrete. The concrete flat test was made to testify the concluded law. The test results show that composite ultra-fine fly ash improves the crack resistance of pavement concrete. The main reason is that it reduces the elastic modulus and drying shrinkage of concrete and improves the ultimate tensile deformation capacity.