Degradation behavior of concrete under corrosive coal mine environment

Abstract

Experimental investigations were taken for the degradation of concrete under coupling effects of hydrochloric acid mist and mixed salt mist consisting of chlorine and sulfate and carbon dioxide according to coal mine environment. Concrete specimens were subjected to four different deterioration time from 45 days to 180 days, with an interval of 45 days. The results showed that the carbonization depth of concrete increased speedy at first, then gently and then rapidly again with the change of fragility. The compressive strength of concrete increased at the initial stage of deterioration, and then decreased until the time of 135 days when they came to the second ascension of small quantity and then entered the decline trend under the coupling effect of carbonization and acid-salt attack. The elastic modulus changed slightly with the deterioration, meanwhile the fragility and ductility changed significantly before and after deterioration time of 180 days, which was identical to the failure modes. Keywords: Deterioration, Coupling effects, Concrete, Properties, Cementitious material