The Resistance of Chloride Ion Penetration and the Microstructure of Air-Entrained Concrete

Abstract

It was investigated that the variation of compressive strength, chloride diffusion coefficient and microstructure of concrete with different water-cement ratio and air content. The experimental results indicate that the bubble distribution and the continuity of the pores in the concrete are greatly affected by the air content in it. It enhanced the discontinuity of the pores and increased the number of tiny bubbles which were independent, closed, stable and equally distributed, as the air content was appropriate. So that it improved the resistance of chloride ion penetration. The chloride diffusion coefficient of C30 concrete whose air content was 5% was only 69.52% of that of theC30 reference concrete. And this effect to C50 concrete was more apparent than C30 concrete.