Abstract: In this paper, the application of Lightweight Aggregate Fiber Shotcrete (LAFS) sprayed layer support in an environment with high groundwater chloride ion content and significant influence of dynamic pressure is used as a background. The orthogonal tests with different erosion ages of NaCl solution and erosion concentrations, ceramic particle admixture and fiber type as influencing factors were designed, compressive, splitting tensile and dynamic compression one-dimensional SHPB impact tests were conducted, and the chloride erosion and fiber reinforcement mechanisms were analyzed with the aid of scanning electron microscopy. The results show that the factors affecting the compressive, splitting tensile and impact performance of LAFS by chloride erosion were mainly the erosion age and the amount of ceramic particles, which showed a trend of increasing and then decreasing with the increase of the erosion age and the amount of ceramic particles. The appropriate amount of pottery granules can make LAFS have certain elastic buffer performance in the chloride salt erosion environment, so that its mechanical and chloride salt erosion resistance can be improved. Under this test condition, the best amount of pottery granules replaces 14% volume rate of stone LAFS. Combined with the LAFS impact damage morphology, it is appropriate to use steel fibers to enhance the mechanical properties of LAFS, followed by basalt and polypropylene fibers.

Key words: light aggregate shotcrete, chlorine salt attack, ceramic granules, fibers, mechanical properties, composites