Cement-based ductile rapid repair material modified with self-emulsifying waterborne epoxy

Abstract

Ordinary silicate cement repair materials are slow to set and harden, have low early strength, and cannot meet the demands of rapid repair, and the disadvantage of brittleness after repair is obvious. Calcium sulfoaluminate cement (CSA) is more suitable for use as a cementitious material for rapid repair materials due to its fast hardening and early strength characteristics, but this cementitious material still suffers from low bond strength and poor toughness, which cannot be effectively resolved. In recent years, polymer-modified cementitious materials have attracted a great deal of attention in the field of repair and reinforcement. Among the many polymer options, epoxy resins have become the most promising choice due to their excellent compatibility and coupling effect with cement hydration and their excellent overall performance. In this paper, a novel waterborne epoxy resin-CSA cement composite restoration material was prepared by using a self-synthesized waterborne epoxy resin (WEP). The mechanism by which WEP improves the performance of CSA cementitious restorative material was also elucidated. The results show that by adjusting the amount of WEP, the workability of the repair material can be regulated. WEP significantly improved the interfacial bond strength of the repair material, and the toughness of CSA cement repair material with 10% WEP increased by 32.2% and the tensile ductility increased by 93.8% compared to the control group. The fully cured WEP and CSA cement hydration products form a dense cross-linked network-like structure, which refines the pore structure of the repair material and improves the disadvantages of the highly brittle and low ductility of the repair material.