Carbonation performance of concrete with fly ash as fine aggregate after stress damage and high temperature exposure

In practical engineering, many factors may cause carbonation-induced corrosion of concrete. In this study, the effects of single factors such as the stress damage and high temperature, as well as a combination of these factors on the neutralization of concrete structures are investigated to evaluate the durability of concrete structures under adverse environmental conditions and promote practical application of concrete with fly ash as fine aggregate (CFA). Rapid carbonation test was conducted to determine the carbonation depths in different carbonation times and evaluate the carbonation resistance of concrete. Results show that the carbonation depth of concrete increases with the increase in the initial stress damage and carbonation time. In addition, compared with ordinary concrete, substituting fine aggregate with fly ash can enhance the carbonation resistance of concrete. High temperature has a noticeable deterioration effect on the neutralization of concrete, and the concrete durability continues to decrease at increasing temperature. The deterioration in the durability of concrete subjected to a combination of high temperature and stress damage is significantly greater than that subjected to a single factor, which significantly reduces the carbonation resistance of concrete, particularly for normal concrete. (C) 2020 Elsevier Ltd. All rights reserved.