Influence of Multi-Phase Carboxylate Salt on Mortar Properties under Sulfate Environment

摘要

A novel multi-phase carboxylate (MPC) salt was prepared by free radical polymerization. Influence of MPC salt on properties of mortar under sulfate environment was investigated. The results from static solution soaking and wet-dry cycling tests indicated that MPC would not bring negative effects on strength and shrinkage of mortar. In particular, MPC was able to reduce the strength loss as a result of inhibiting the generation and growth of ettringite in static solution soaking test. The crystal expansion of AFt was reduced since the Ca~(2+)dissolution and SO42" ingress were less. Meanwhile, the strength loss of mortar under sulfate wet-dry cycling could be reduced as well by MPC. MPC inhibited the growth of CaSO_4-2H_2O crystals by replacing the functional groups. The growth of micro-cracks in cement paste was inhibted and the the risk of crystal expansion and destruction of mortar was reduced. It was believed that MPC exhibited an excellent sulfate attack resistance for mortar.