Influence of freeze-thaw cycles and sulfate corrosion resistance on shotcrete with and without steel fiber

In this study, the performances, including relative dynamic elastic modulus, mass loss ratio, and mechanical properties after corrosion, were tested to investigate the shotcrete durability of frost and sulfate resistance. Then, mineral composition, thermal analysis, pore structure, and microscope analysis of the specimen before and after corrosion were characterized. To achieve this objective, ordinary concrete and accelerated shotcrete with and without steel fiber were fabricated. Results showed that ordinary shotcrete was more durable under the action of freeze-thaw cycles and sulfate ion attack than that of the ordinary concrete with the same mixture. Thus, steel fiber led to a considerably dense microstructure in the shotcrete matrix, and it could significantly improve the early-age compressive and splitting tensile strengths. Steel fiber reinforced shotcrete had the best durability performance in frost and sulfate resistance.