Influence of curing conditions on recycled aggregate concrete

This paper presents the results of a study of permeability and its influence on the durability of recycled concrete exposed to an aggressive environment. Recycled concretes with 20%, 50% and 100% in weight of recycled aggregate and 24 effective w/c ratios have been exposed directly to a marine environment. Control specimens cured in a humidity chamber have been also tested in order to compare the influence of the curing environment. The durability of recycled aggregate concretes exposed to aggressive conditions decreases in terms of permeability, as the results show. However, the influence of the environment on the recycled concrete also depends on the quality of the cement paste. The differences between the control and the exposed concrete are lower for low water/cement (w/c) ratios. The lower capillarity obtained in the new cement paste of the recycled concretes with low w/c ratios isolates the porosity of the recycled aggregate, increasing the durability but with a rise in the cement content.