Elasto-Damage Constitutive Modelling of Recycled Aggregate Concrete

Abstract

Use of recycled aggregates in concrete has proved to be beneficial in attaining sustainable construction without compromising overall material and structural performance when compared with concrete containing natural aggregates. However, use of the recycled aggregates in concrete have resulted in reduction in compressive and tensile strengths with the recycled aggregates percentage increase in concrete. Furthermore, it is important to note that most of the finite element software used in the construction industry use concrete model derived from the test results of the conventional concrete, therefore, they may not always predict safe solution for recycled aggregates concrete (RAC). Therefore, in this investigation elasto-damage, proposed by Khan and Zahra, for natural aggregate concrete (NAC) was modified to incorporate the influence of recycled aggregates on the behaviour of concrete. Model use four parameters α, β, γ critical energy release rate (Rc) to predict the behaviour of recycled aggregate concrete for multi axial stress states. Parameters α, β and γ are used to predict the different behavior of concrete in tension and compression while Rc controls the damage growth rate. These parameters are defined as a function of concrete compressive strength (fc/) and its initial elastic modulus (Eo). Existing test results for uniaxial compressive state of stress were used to validate this model and it was found that it predicts better post cracking and post peak-behaviour of RAC as compared to the commercially available models for conventional concrete