Influencing factors and optimization on mechanical performance of solid waste-derived rapid repair mortar

There is a great demand for high performance rapid repair mortar (RRM) because of the wide use of cement concrete. Solid-waste-based sulfoaluminate cement (WSAC) is very suitable as a green cementitious material for repair materials because of its characteristics of high early-age strength and short setting time. However, the influence and optimization of various factors of WSAC-based RRM, such as water-to-RRM ratio, binder-to-sand ratio and additives, as well as the further solid waste replacement of aggregate, remain to be studied. This paper comprehensively studied the influence of the above factors on the performance of WSAC-based RRM and obtained a green high-performance RRM by optimizing these factors. The experimental results showed that the early and late strength of the obtained RRM is excellent, and the setting time and fluidity are appropriate, which reflected good mechanical properties and construction performance. Ordinary Portland cement (OPC) doping could not improve RRM strength. It was feasible to prepare RRM with gold tailing sand replacing part of the quartz sand. This paper provides data and a theoretical basis for the preparation of high-performance RRM based on solid waste, expanding the high value utilization of solid waste, which is conducive to the development of a low carbon society.