A flame-retardant corn straw brick (FRCSB): Thermal stability, flammability and flame-retardant mechanism

The use of corn straw in brick is significant for the utilization of agricultural waste and the improvement of brick’s properties. This research investigated the thermal stability, flammability, and the flame-retardant mechanism of flame-retardant corn straw brick (FRCSB). The results show that the FRCSB could stand the test of heat treatment, and has good flame retardant properties. The occurrence temperature of chemical reactions was rose, and the occurrence moment of chemical reactions was postponed due to the calcium carbonate barrier on the surface of FRCSB and the air untouchable corn straw fiber well covered with calcium hydroxide. The growth of crevices destroyed the FRCSB surface, leading to the pyrolysis of deeper corn straw fiber and calcium hydroxide, weight, dimensions, color changes, and promoting the thermal mass exchange between the FRCSB and the air. The strong alkali environment provided by calcium hydroxide enables the corn straw fiber to maintain its own characteristics for a long time, and then plays the role of support and connection, which promotes the performance of FRCSB during heat treatment.