Experimental study on the rheological property of cement paste with fly ash and brick powder

The purpose of this study is to investigate how the inclusion of brick powder (BP) and fly ash affects the rheological behavior of fresh paste, and to analyze the underlying mechanism of these mineral admixtures. The study examines the water film thickness and interparticle force through calculation, and the yield stress and viscosity through measurement and derivation. The results suggest that mineral admixtures can reduce the water film thickness of fresh paste, with attractive forces between cement and BP promoting flocculation, and repulsive forces between other particles contributing to particle dispersion. The addition of BP results in an increase in yield stress, viscosity, and thixotropy of the fresh paste. The use of fly ash and BP as mineral admixtures prove to be an effective approach to controlling the rheological properties of fresh paste.