Study on the Early Effect of Excitation Method on the Alkaline Steel Slag

Abstract

The change law of alkaline steel slag cementitious activity was investigated by mechanical excitation, alkaline excitation, and salt excitation methods. The effect of grinding time, chemical activators, and content of steel slag on the properties of cement replaced by steel slag was studied. The hydration products of cement replaced by steel slag were analyzed by XRD and SEM. The results show mechanical excitation can effectively improve the particle size distribution and cementitious activity of steel slag. The best mechanical properties are obtained when grinding for 20 min and adding 10% steel slag. Chemical excitation can further improve the cementitious activity of steel slag based on mechanical stimulation. The optimal mechanical properties are obtained when the dosage of sodium hydroxide is 1.0%, the dosage of early strength agent is 2.0%, and the dosage of steel slag is 25%. The main hydration products of cement replaced by steel slag are calcite (CaCO3), calcium hydroxide (Ca(OH)2), dicalcium silicate (Ca2SiO4), and C-S-H gel. The microstructure presents a fibrous network structure, laying the foundation for improving mechanical properties.