Abstract: To solve the problems of cracking of slurry and serious deformation of roadway in ordinary concrete shotcreting support,wet shotcreting steel fiber silica fume concrete was proposed.The effects of steel fiber content and shape,silica fume content and water reducer content on flexural strength of concrete were studied through experiments.Then,the optimum proportion of steel fiber silica fume concrete was obtained.It was applied to the shotcrete support of the return air inclined shaft in a mine.The results showed that the flexural strength of concrete improved by wavy steel fibers was much greater than that of straight steel fibers.The optimum incorporation rate of wavy steel fibers was 1.5%.The optimum content of silica fume was 10% of that of cement.The optimum dosage of water reducing agent was 0.6%.The feasibility of controlling the surrounding rock of roadway by steel fiber silicon powder concrete shotcrete support is proved by spray layer stress monitoring and surrounding rock deformation observation.

Key words: Shotcrete support,Steel fiber,Silicon powder,Concrete,Flexural strength