The Performance of Sulfoaluminate Cement Mortar with Secondary Aluminum Dross

This paper endeavors to explore the impact of secondary aluminum dross (SAD) on the characteristics of sulfoaluminate cement mortar. Measurements were taken for the mortar’s slump flow, plastic viscosity, initial setting time, and drying shrinkage rate (DR). Additionally, the flexural, compressive, and bonding strengths were evaluated. The leached concentrations of chromium (Cr) and zinc (Zn) in the specimens were determined. Furthermore, the carbonation depth (Dc) and chloride ion migration coefficient (CMC) were calculated. Lastly, scanning electron microscope energy spectrum analysis (SEM-EDS) and X-ray diffraction (XRD) spectrum analysis were conducted to analyze the mortar’s performance. The findings revealed that the slump flow and plastic viscosity of fresh mortar exhibited negative and positive quadratic relationships, respectively, with the mass ratio of SAD. Specifically, SAD could reduce the slump flow by 1.57% to 2.72% and augment the plastic viscosity by 5.21% to 36.89%. The placement time contributed to a decrease in the slump flow of fresh mortar by up to 20.4% and an increase in plastic viscosity by up to 11.2%. The initial setting time, mechanical strength, and DR of the mortar demonstrated quadratic variations with the mass ratio of SAD. At a 15% SAD mass ratio, the mortar exhibited the highest initial setting time, mechanical strength, and DR. The inclusion of SAD could elevate the initial setting time, flexural strength, compressive strength, bonding strength, and DR of the mortar by 14.33% to 65.07%, −14.75% to 22.58%, −8.94% to 9.96%, −13.33% to 66.67%, and −13.33% to 26.67%, respectively.