Effects of CaCO3 whisker on the physical properties of cement composites

CaCO₃ whiskers were incorporated into cement composites in this paper and the effects of whiskers on the physical properties of cement composites were studied, including the fluidity and dry shrinkage of mortar and the pore structure of cement paste. The results showed that the fluidity of cement mortar was decreased gradually with the CaCO₃ whisker content increasing and when the whisker content was in the range of 10%, the fluidity had no significant degradation; when the whiskers were mixed in the mortar with the content of 5% and 10%, the effect on the dry shrinkage of mortar was not obvious and with the content increasing further, the dry shrinkage was increased; through the analysis of mercury intrusion porosimetry(MIP) test, it was shown that the porosity of cement paste was increased with the whisker content increasing and when the content was less than 20%, there was no significant change in the main distribution of pore size and the increase of less harmful pores below 50nm was dominant.