Experimental Analysis of Relationship between Pore-Structure and Frost-Resistance of Concrete

Abstract

The influence of admixture on concrete pore structure was analyzed by using the mercury intrusion method and the rapid frozen-thaw method under the condition of the same water/binder ratio in this paper, and thus the relationship between pore structure and frost resistance of concrete were analyzed. When the compound mineral ad-mixture is mixed, the porosity rate of concrete can be decreased and the harmful hole is in-creased, the less-harm hole and the no-harmful hole are decreased. The early strength of concrete is not decreased. But the strength has the increasing trend in the late, which is more favorable for the impermeability and corrosion resistance. But the improvement of the freezing resistance is not obvious. The admixture of air entraining agent can increase the porosity and more-harmful hole, and the concrete strength will be decreased, which will be not favorable for the freezing resistance of concrete. If these two substances are admixed at the same time, the concrete porosity is increased, and the pore size distribution of concrete can be reasonable. The decrement of concrete strength is not obvious, but it is favorable for the freezing resistance of concrete.