Stress-Strain Behavior of Mortar Mixtures Containing Construction and Demolition Waste as Fine Aggregate

Abstract

In this paper it was investigated how the use of recycled fine aggregate influences the stress-strain behavior of mortar mixtures with different strengths. The mix design composition of the studied mortars, expressed by mass, were 1:2:0.45, 1:4:0.68 and 1:6:1.05 (cement: sand: water/cement ratio). The substitution percentages by mass of the natural aggregate by recycled aggregate were 15, 25 and 50%. The recycled aggregate had a grain size distribution comparable to that of natural sand and was obtained by grinding the waste produced by the partial demolition of UFRJ’s University Hospital. The mortars were evaluated under uniaxial compressive strength test after 28 days of curing. The results indicated that for the two higher strength classes the substitution rates affects its mechanical response by decreasing the strength. Besides, for the lower strength class the recycled aggregate could promote an increase of strength in the case of 25% of replacement.