Study on preparation of ettringite-based fireproofing material for cable trench and its fireproofing mechanism

Abstract The construction of a new power system puts forward higher requirements for the fire safety of power equipment. Fiber cement board is a kind of fire-proof material for cable trenches in electric power fields, but it cannot meet the requirement of electric fire protection. In order to meet the new requirement of high fire-proof grade for cable trench in substation, Ettringite-rich fire-proof separating material was prepared by using a metallurgical slag-sulphoaluminate cementitious system. The high temperature behavior of samples was studied by high temperature calcination test, thermal analysis and microstructure observation. The results show that the temperature rise of ettringite cementitious material is 5.2°C and 22.1°C lower than that of fiber cement board at 500°C and 1000°C respectively, and it can be used in the field of fire protection of substation cable trench. The reversible decomposition of ettringite is the main reason why ettringite-based cementitious materials can be reused.