Experimental Study on Strength and Pore Structure of Cement Mortar in Early Freezing Environment

The pore structure of early freezing cement mortar was tested by mercury intrusion porosimetry. The pore size distribution and compressive strength of mortar with different water-cement ratio, curing period, age and temperature were studied. The effects of pore size distribution on the compressive strength with early freezing conditions were discussed. The results showed that both the short-term strength loss and the long-term strength loss were not serious in the negative temperature environment, and the negative temperature made the pore of 10-100nm increased, while reducing the 100-2000nm; The pore above 2000nm had little effect on the compressive strength and the pore of 10-2000nm played a major role in the effect of compressive strength, besides, the pore of 100-2000nm affected the long-term strength growth; Curing period affected the pore above 2000nm, the shorter the curing time, the higher the porosity in this range, and superplasticizer could significantly increase the pore above 2000nm.