Concreto auto adensável com agregado miúdo reciclado de concreto

Abstract

A more sustainable approach in the production of self-compacting concrete (SCC) aims to replace the natural aggregates by recycled concrete aggregates, however this substitution affects the properties of the concrete produced. This research propose evaluate the effect of the fine recycled aggregate on the properties in the fresh and hardened state of self-compacting concrete using a methodology of dosage focused on the rheology of materials. The dosage study was performed through an adaptation of the Gomes method, and four levels of FNA substitution by FRCA were determined (10%, 20% and 30%). Were analyzed the fresh state properties according to the parameters established according to the specifications on the subject and by the normative prescription of reference, and the properties in the hardened state. In this study, was observed a decrease in apparent viscosity, passing ability and segregation resistance, proportional to the increase in FNA substitution. However, all mix designs have attend the required of self-compacting, with minimum adjustments. All concretes obtained axial compressive strength at which fit in the structural concrete class. Therefore, through the responses founded during the dosing study, it was possible to produce self-compacting concretes with 30% of FRCA that met the requirements established.