Test and analysis of the flexural performance of sandwich insulation wall panels with textile-reinforced engineered cementitious composites in wythes after hot rain cycles

A sandwich insulation wall panel is a novel composite wall that integrates load bearing, thermal insulation and decoration. Most of the wall materials of sandwich insulation wall panels are made of ordinary concrete or lightweight concrete, which causes the wall panels to be too thick and heavy, and there are problems associated with poor durability and high energy consumption. Textile-reinforced engineered cementitious composite (TRE) materials have excellent mechanical properties, toughness and durability. Therefore, a type of sandwich insulation wall panel (SIWP) was constructed using textile-reinforced engineered cementitious composites (TRE) as the inner and outer wythes. Its good crack control ability and tensile performance can compensate for the brittle cracking and shedding of ordinary concrete sandwich insulation wall panels. Through a four-point bending test, the bending performance of the TRE sandwich insulation wall panel (TRE-SIWP) was analyzed from three aspects: failure mode, load-midspan deflection curve and ductility. The research variables included the number of hot rain cycles, the thickness of the TRE wythes, the hot rain environment, the thermal insulation layer type and thickness, and the number of heating-freezing cycles. The results show the that hot-rain cycles had the least effect on the specimen with a rock wool board, and they caused more damage to the TRE wythes than they did to the insulation board. Increasing the thickness of the insulation layer and TRE width could improve the flexural bearing capacity and stiffness of the TRE-SIWPs.