Issue 67

D. Fellah et alii, Frattura ed Integrità Strutturale, 67 (2014) 58-79; DOI: 10.3221/IGF-ESIS.67.05

a)- Recycled concrete RC30 .

b)- recycled concrete RC50

c)- Recycled concrete RC70 .

d)- recycled concrete RC100. Figure 13: Results of numerical modelling for different fraction of recycled aggregates.

C ONCLUSION

T

his paper presents an experimental and numerical study on recycled concrete. The following remarks and conclusions can be drawn from this work: 1. The experimental work involved uniaxial compression tests on natural concrete (NC) and recycled concrete (RC) with different substitution rates of natural aggregates (NA) by recycled aggregates (RA). The stress-strain curves obtained from these tests showed that the addition of recycled aggregates in the concrete affects its mechanical properties in both the fresh and hardened states. Specifically, the incorporation of recycled aggregates in new concrete leads to a decrease of the Young modulus and the compressive strength, and an increase of the maximal strain. 2. A linear elastic homogenization model for recycled concrete is established by combining the GEEE-MT-Voigt methods through a three-step homogenization procedure. This model is then extended to the nonlinear regime by using a secant formulation. Mazars damage law is incorporated into the model to describe the softening behavior. The recycled concrete can be simulated as a three-phase composite by using the proposed homogenization procedure. 3. The proposed homogenization model was validated by comparing the numerical results with the experimental behavior of NC and different RCs. The numerical predictions show a good agreement with the experimental results for different substitution rates.

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