Investigating the failure process of concrete under the coupled actions between sulfate attack and drying-wetting cycles by using X-ray CT

X-ray CT was implemented to investigate the failure process of concrete material under the coupled actions between sulfate attack and drying-wetting cycles. Macroscopic performance of concrete and microcosmic variation of concrete pores under sulfate attack combined with drying-wetting cycles were experimentally investigated, and then the correlation between them was analyzed by using grey incidence theory. The results showed that the coupled actions from sulfate attack and drying-wetting cycles intensified the damage of interior structure of concrete pores. The higher concentration of salt solution was, the more serious damage of pore structure was. Drying-wetting cycles coarsened the pores of concrete specimens so that the sulfate was more prone to enter the interior of concrete, thereby accelerate the failure of concrete material. (C) 2016 Elsevier Ltd. All rights reserved.