Influence of SCM on the Permeability of Concrete with Recycled Aggregate

The article presents experimental analysis of concretes mixed by using natural and low quality recycled concrete aggregate (RCA). The resistance of concretes with both, RCA and supplementary cementitious materials (SCM) to penetration in aggressive environmental conditions was studied. The influence of fly ash, microsilica and metakaolin on the concrete permeability was investigated. Besides the fundamental mechanical properties of concrete, sorptivity, water absorption, depth of penetration of water under pressure and chloride migration coefficient were tested. The significant effect on the permeability of RCA and SCM is described and discussed. The replacement of the natural aggregate by RCA decreased the concrete resistance to penetration of aggressive media, but the application of the SCM significantly reduced this negative impact.