Influência da substituição parcial de agregados graúdos de RCD classe vermelho em concretos autoadensáveis

Abstract

This work produced and characterized autoadensáveis concrete (CAA) with partial replacement of natural coarse aggregate by coarse aggregates from construction and demolition waste red class. The assay technique chosen for the CAA production was to Gomes, Gettú and Agulló. The traces for the concrete production were developed from the composition of two granular skeletons, the first in order to obtain the best percentage of substitution between natural coarse aggregate and recycled coarse aggregate, and another to determine the ratio of this mixture and the added natural kid. Thus, four mixtures were set a self-compacting concrete without recycled aggregate replacement called CAAREFERÊNCIA, another mixture containing 40% of recycled aggregate (CAA40%) a self-compacting concrete with 50% recycled aggregate (CAA50%) and a self-compacting concrete 60% recycled aggregate (CAA60%). These mixtures had their rheological and mechanical properties analyzed. In fresh tests were carried out to assess the passing ability in Box-L, Box-U and Ring- J, the apparent plastic viscosity in the flow of testing time (t500) and test the funnel-V, and workability for Slump flow test and inverted cone, the results show that with the partial replacement of natural coarse aggregate by recycled coarse aggregate mixtures showed higher viscosity, reduced passing ability and fluidity. As for mechanical analysis were performed strength tests to axial compression and diametral compression traction indicated that, in the hardened state, the CAA60% mixture obtained the best results in both trials. Additionally, the compressive and tensile strength results were compared with the results obtained for a CAA partial substitution with natural coarse aggregate by coarse aggregate from construction and demolition class gray residue, which showed that at 7 days the CAA produced with Construction and demolition waste red, mostly acquired greater resistance, but at 28 days the CAA with gray Construction and demolition waste reached higher resistance in all substitution percentages.