Influência da substituição parcial de agregados de RCD classe cinza em concretos autoadensáveis

Abstract

This work produced and characterized autoadensáveis concrete (SCC) with partial replacement of natural coarse aggregate by coarse aggregates of construction waste and demolition gray class. The dosage used was the method Gomes, Gettú and Agulló. The traits of the concretes produced were determined from the composition of two skeletons, a granular to determine the proportion of coarse aggregate natural would be replaced by coarse aggregate from construction and demolition waste and another to determine the proportion of this composition with the aggregate natural kid. So four mixes were defined, self-compacting concrete reference (SCCREF), self-compacting concrete with 40% of coarse aggregate from construction and demolition waste (SCC40%), 50% of self-compacting concrete with coarse aggregate from construction and demolition waste (SCC50%) and autoadensável concrete with 60% of coarse aggregate from construction and demolition waste (SCC60%). Mixtures had their rheological and mechanical properties analyzed. Fresh tests were performed to evaluate the passing ability in the L-Box and J-Ring, plastic viscosity apparent in the time of disposal (t500) and V-Funnel test, and workability for Slump flow test and Inverted cone, the results obtained show that the partial replacement of coarse aggregate by recycled coarse aggregate natural mixtures presented a higher viscosity, decrease in passing skill and fluidity. As for the mechanical analysis were conducted the tests for resistance to axial compression and tensile by diametral compression on the bodies-of-proof of concrete that indicated that in hardened, the mixture SCC 40% presented better results in two trials, and it was observed that none of the samples subjected to traction by diametral compression presented apparent segregation of aggregates.