Properties in fresh state of mortars with recycled aggregate concrete and effect of c/a relation

Abstract

Construction and Demolition Residues have become a complex-to-manageand expensive urban problem, so currently an environmental legislation isinnovated in order to promote activities to mitigate it being the recyclingone of the more accurate (it empowers the reintegration as second generationmaterial for new use in construction). Considering the previouscomments, some studies with mortars have been developed, where thenatural aggregates are replaced by different percentages of residues,since there are not legislation or regulation that propose them. However,there are few investigations about the behavior of these concretes in freshstate, linked them with theirs properties in the posteriori hardened state.In this investigation, tests of properties in fresh condition (consistency,density and content of air) of mortars containing different percentagesof recycled concrete aggregates as substitution of natural aggregates (10,20, 30, 50 and 100%) and with different cement/sand rates (1:3.25, 1:4and 1:4.74), have been realized. The results obtained show that mortarswith recycled aggregates present a lower density, need more quantity ofwater to achieve the required consistency, and have higher air contentthan the reference mortars.