Constitutive Model for Recycled Aggregate Concrete

Abstract

In this paper, the Performance Dependent Model previously proposed by Folino & Etse is reformulated in order to capture the mechanical behavior of Recycled Aggregate Concrete (RAC), a special type of concrete in which natural coarse aggregate content is partially or totally replaced by recycled aggregates obtained from the crushing of waste concrete. The model depending on the three stress invariants, has a non associative flow rule, a non uniform hardening law, and a softening law based on the fracture energy of modes I and II.
Regarding sustainability issues, RAC is of particular interest considering that it permits to reduce construction demolition waste and the use of natural aggregates. From the point of view of structural engineering, it is necessary to identify the main features of its mechanical behavior in order to accurately predict the structural behavior of structures using this material.
In this work, the input parameters of the model are reformulated for RAC considering the main features of its failure and mechanical behavior. Numerical predictions of peak stresses obtained with the proposed failure criterion included in the approach are validated against experimental results including uniaxial compression and triaxial compression tests, and numerical experiments showing the behavior under uniaxial compression are presented.