Statistical analysis of mesoscopic concrete with random elastic modulus

In this paper a meso-concrete model is established by using cohesive element script and random aggregate procedure to investigate the influence of elastic modulus on the mesoscopic concrete properties, where the crack is simulated by the deletion of cohesive element. The meso-structure parameters of concrete specimen with homogeneous elastic modulus are investigated based on the model, such as aggregate shape, aggregate diameter and interfacial initial imperfection. The analysis results show that aggregate shape and diameter have an influence on the concrete behavior, and the decrease of aggregate diameter is recommended to improve the concrete strength. Interfacial initial imperfection has an obvious significance on concrete tension peak stress, and the tension strength declines by 67.9% when the interface between aggregate and mortar is all initial imperfection. Furthermore, a new method is proposed that mortar elements are randomly assigned in different elastic modulus sets for considering the non-uniformity of mortar. This method can contribute to promoting the feasibility from the ideal model to the real. Numerical examples are analyzed in order to verify the necessity of importing the non-uniformity, and a safety coefficient is recommended as 0.85 for considering the adverse effect of elastic modulus randomness of mortar.