A numerical method for the prediction of elastic modulus of concrete

Concrete is usually considered to be a two-phase material for the prediction of its mechanical properties. More research has, however, shown that there exists an interfacial transition zone (ITZ) between aggregates and cement paste. As such, concrete should be modelled as a three-phase material at a mesoscopic level. This paper presents a numerical method that can predict the elastic modulus of three-phase concrete with reasonable accuracy. In this method, the mesostructure of concrete is simulated and the finite element method is employed for the stress analysis in the concrete. In addition, the method modifies the lattice model to take account of the mechanical properties of each phase constituent of concrete in the finite element analysis. The results produced by the proposed numerical method are compared with those by analytical methods. Finally the numerical results are verified by experimental results obtained from research literature. Based on the results presented in the paper, the effects of the aggregate area fraction, the elastic modulus ratio of aggregate to cement paste and the elastic modulus ratio of ITZ to cement paste on the overall elastic modulus of concrete are examined.