Hardened state behavior of beneficiated recycled aggregate concrete

Abstract

This study presents the results of an experimental investigation performed on hardened state properties of concrete made with coarse Recycled Concrete Aggregates (RCAs) as an alternative aggregate to natural coarse aggregates. Physical characteristics of the coarse recycled aggregates were improved by adopting three different beneficiation techniques i.e. chemical beneficiation, mechanical beneficiation and chemical-mechanical beneficiation. Consequent upon the use of non-beneficiated and beneficiated aggregates in the production of Recycled Aggregate Concretes (RAC), the change in properties of the concrete are reported in terms of their compressive strength, chloride-ion penetration resistance, initial surface absorption, capillary suction and ultrasonic pulse velocities. Results of the investigation showed a loss in hardened state properties of concrete while using RCAs in place of natural aggregates. However, properties of RACs could further be improved and loss in hardened properties could be compensated with utilization of beneficiated RCAs in place of non-beneficiated RCAs at the same replacement levels.