Recycled aggregate concrete - Mechanical behavior under uniaxial and triaxial compression

This paper presents the results of an experimental program related with the failure and mechanical behavior of Recycled Aggregate Concrete (RAC) under different load scenarios. The particular type of RAC considered herein is characterized by the partial or total replacement of natural coarse aggregates by recycled ones obtained from the crushing of waste concrete. The aim of this research is to deepen the existing knowledge related to RACs by analyzing the degradation in physical and mechanical properties when recycled coarse aggregates are used. In particular, its behavior under triaxial compression is examined. A normal strength concrete with natural coarse aggregates was designed and used to produce cylindrical samples which, after being tested, were crushed and reused as coarse aggregates in the elaboration of RAC. Samples were subjected to uniaxial compression, splitting tensile and triaxial compression tests. Experimental results related to the physical properties of recycled aggregates, fresh concrete properties, and hardened concrete mechanical behavior are presented and discussed. Moreover, the Performance Dependent Failure Criterion based on an objective definition of concrete quality, was extended and applied to predict peak stresses of RAC under triaxial compression. The comparison of experimental and numerical results demonstrated that this criterion originally developed for standard concrete is also suitable for RAC. (C) 2014 Elsevier Ltd. All rights reserved.