Expansion of mortars with gypsum contaminated fine recycled aggregates

This study evaluates the expansivity of fine recycled aggregates mortars depending on the type of Portland cement, the consistency and the equivalent of acid soluble sulphates (SO3) content. For that, an experimental campaign divided in two phases was performed. In the first phase, the cement pastes were produced and tested by means of X-rays diffractions in order to analyze the hydrated compounds formed over time. In the second phase mortars samples were cast in order to assess the physical and mechanical properties as well as the expansion over time. The results showed that incorporation of gypsum contaminated fine recycled aggregates with SO3 contents up to 2.9% by weight does not compromise the durability in mortars, regardless of the cement types studied in this study, the consistency and the contaminant present. (C) 2012 Elsevier Ltd. All rights reserved.