Study on Mechanical Properties of High Fine Silty Basalt Fiber Shotcrete Based on Orthogonal Design

In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS.