Effect of transition zone on the elastic behavior of cement-based composites

Abstract The elastic behavior of mortar and concrete as a composite material and the influence of the transition zone on the elastic modulus is studied. The theoretical bounds of Hashin-Shtrikman for the modulus of elasticity of two-phase composite material are used as a criteria in the analysis. Available experimental results with variable W C ratio, aggregate volume and variable E-modulus of the matrix and the aggregate are considered. A notable influence of the transition zone on the elastic behavior of the composite is detected. It is demonstrated as a divergence of the experimental data from the general trend of the theoretical bounds with the increase of the aggregate volume. The influence of the transition zone on the overall elastic properties of the composite is strongly related to the water content and with the reduction of W C ratio it changes from negative into positive.