Based on single shotcrete lining structure of tunnel engineering, the mechanical and permeability performance of shotcrete with

different water/binder ratios (w/b),  fly ash replacements and steel fiber replacements were studied. Results showed that the early-age

strengths of shotcrete were stronger than those of normal concrete. When the curing age was more than 1 day, however, the strengths of

shotcrete were poorer than those of normal concrete. Moreover, with the increase of w/b and the decrease of amount of steel fiber, the

permeability and strengths of shotcrete would decrease. And with the increase of fly ash replacement, the compressive strength of

shotcrete may firstly increase and then decrease, the permeability may firstly decrease and then increase, while the splitting tensile

strength may continuously increase. Furthermore, the durability and mechanical performance of shotcrete with erosion  were studied and

compared with those of normal concrete. It was found that the chloride ion concentration  in shotcrete was higher than that in normal

concrete. However, the carbonation, freezing and thawing, and sulphate resistance of shotcrete were better than those of normal

concrete. The inclusion of steel fiber can improve the durability of shotcrete, but the chloride ion concentration in shotcrete was

still higher than that in normal concrete.