Effect of Nano-CaCO3 on Properties of Cement Paste

In this paper, effect of nano-CaCO3 (NC) on properties of cement paste was studied. Experimental results showed that NC had no effect on water requirement of normal consistency of cement. However, with the increase of NC content, the flowability decreased and the setting time of fresh cement paste was shortened. The early hydration of cement was activated by NC. The strength and the early age shrinkage of cement paste were also studied. Mechanical experiments indicated that the flexural and compressive strength of hardened cement paste increased with the addition of NC at the age of 7d and 28d, and the optimal content of NC was 1%. The early age (12 h) shrinkage of cement paste containing 1% NC was the most prominent which could decrease the shrinkage strain obviously.