Effects of supplementary cementitious material(SCM) on carbonation resistance of concrete

Abstract

Using fly ash (FA) and ground granulated blast furnace slag (GGBS) as representatives of supplementary cementitious material (SCM), the effects of the amount and combination of SCM addition on the carbonation resistance of concrete were systematically analyzed through rapid carbonation tests. Combined with XRD chemical analysis and DSC-TG thermogravimetric analysis, the influence mechanism of SCM on the carbonation resistance of concrete was discussed. The research results indicate that the addition of SCM increases the carbonation depth of concrete.

When the single addition of FA exceeds 40%, the carbonation depth of concrete increases very quickly. Under the premise of the same total addition amount, the carbonation resistance performance of the composite FA and GGBS groups of concrete is better than that of the single FA group. Among the different combinations of FA and GGBS, the concrete with S95 grade GGBS+ grade I FA has the best carbonation resistance. The impact of FA on the carbonation resistance of concrete is manifested as a positive and negative effect.