Abstract:Studying the impact of typical mineral admixtures on the rheological behavior and reaction rate of cement mortar is of significant importance for regulating the early working performance. This paper investigates the effects of four commonly used mineral admixtures in cement-based materials (blast furnace slag, fly ash, steel slag, and limestone) on the rheological parameters (time-dependent torque, yield torque, and relative viscosity), shear failure modes, and reaction processes (hydration heat release) of fresh cement mortar. Additionally, the relationship between the influence of different admixtures on the rheological behavior and the reaction process is also explained. The findings indicate that a 10% dosage of mineral admixtures all strengthens the structural formation capacity of cement mortar, while a 30% dosage delays the structural formation rate of the fresh mortar. A high dosage (30%) of fly ash delays the occurrence time of shear slip in cement mortar, while steel slag shows the opposite effect. The addition of 30% fly ash and blast furnace slag reduces the yield torque to varying degrees (the case of limestone is similar to that of fly ash), while steel slag significantly enhances the yield torque and relative viscosity. The hydration heat release results reveal that the variations in the rheological behavior of cement mortar containing mineral admixtures are respectively related to the nucleation effect of fly ash and limestone, as well as the participation of blast furnace slag and steel slag in the cement hydration process, which changes the early-age reaction characteristics of cement mortar
李端乐, 吴小缓, 廖述聪, 孟 翔, 汪 坤, 吴佳炜. 矿物掺合料对水泥砂浆流变行为的影响研究[J]. 水泥杂志, 2025, 0(06): 1-.
LI Duanle, et al.. Research on influence of mineral admixtures on rheological behavior of cement mortar. Journal of Cement, 2025, 0(06): 1-.