Investigation of a new type of thermal insulation shotcrete with silicone rubber tubes (SSRT)

In order to solve the high temperature problem faced in underground engineering, a method of laying silicone rubber tubes (SRTs) in the anchor net structure to form a new type of thermal insulation shotcrete with SRTs (SSRT) is proposed in this paper. The mechanical and thermal insulation performances of SSRT are investigated, as well as the correlation between SRTs sizes and compressive strength, splitting strength and thermal conductivity. Results show that SSRT has increased the thermal insulation performance of 44-71% compared with ordinary Portland shotcrete (OPS), and the mechanical performance is affected to varying degrees. Based on the experiments in this paper, the optimal SRTs laying process parameters of SSRT are determined, i.e. SRTs with an outer diameter of 8 mm, an inter diameter of 3 mm and a distance of 8-9 mm between SRTs. This investigation provides a new exploration and theoretical basis for shotcrete support and insulation technology in high ground temperature environments.