Resistance of phosphogypsum-based supersulfated cement to carbonation and chloride ingress

The search for cements with lower CO2 emissions and lower consumption of non-renewable materials has been a challenge for the cement industry. The aim of this study was to investigate the resistance of SSC concrete to carbonation and chloride ingress. Portland cements (CEM I and CEM III/B) were used as a comparison. The results showed that the carbonation was very advanced in the SSC concretes. This is related to the exclusive formation of C-S-H and ettringite as hydration products, which present a higher rate of carbonation than portlandite. The SSC concrete has a good performance in terms of chloride penetration, mainly due to the increased ability to combine chloride ions both physically and chemically. The service life estimation showed that SSC concretes could be suitable for rural and urban environments when low w/c ratios (0.40) are used. All SSC mixtures studied were suitable for chloride environments. (C) 2020 Elsevier Ltd. All rights reserved.