A study on effect of P_2O_5 on the mineral structure and properties of sulphoaluminate clinker

摘要

The effect of different amount of P_2O_5 additive on formation and properties of Sulphoaluminate clinker has been studied. Results show that the phosphorus adulterated doesn't alter the key mineral composition of clinker, but affects the crystal structure of major minerals remarkably. With the increase of P_2O_5 content, the normal consistency of clinkers decreases gradually and setting time extends. Comparing with blank sample Ao, the early compressive strength of specimens containing phosphorus increases obviously, however, their strengths at 28 days all drop with different degree except sample A_1 containing a little phosphorus. The probable reason is the damage expansion made by excessive P_2O_5 inhibitting the early hydration of C_4A_3S and making it go on forming large ettringite after hardening of pastes.