Effects of Initial Defects on Effective Elastic Modulus of Concrete with Mesostructure

An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete, in which concrete is realized as a four-phase composite material consisting of coarse aggregates, mortar matrix, interfacial transition zone (ITZ), and initial defects. With the three-dimensional (3D) finite element (FE) simulation, the highly heterogeneous composite elastic behavior of concrete was modeled, and the predicted results were compared with theoretical estimations for validation. Monte Carlo (MC) simulations were performed with the proposed mesostructure model to investigate the various factors of initial defects influencing the elastic modulus of concrete, such as the shape and concentration (pore volume fraction or crack density) of microspores and microcracks. It is found that the effective elastic modulus of concrete decreases with the increase of initial defects concentration, while the distribution and shape characteristics also exert certain influences due to the stress concentration caused by irregular inclusion shape.