Predicting the Time-dependent Mechanics of Concrete Based on a Multiscale Model

Abstract

To accurately predict the time-dependent deformation of concrete, a multiscale model with its focus pinned on mesoscale is proposed here to break down the constitutive law of concrete to the mechanics of its different constituent phases. A three-phase unit cell, consisting of one coarse aggregate, mortar matrix, and the interfacial transition zone (ITZ), is employed to represent the basic structural element of concrete on mesoscale. Following Eshelby’s inclusion theory, the Mori-Tanaka homogenization, continuous retardation spectrum method, and isotropic continuum damage model are applied to capture the time-dependent behavior of the unit cell. To take into account the shape effect of aggregate, the explicit Eshelby’s tensor of polygonal inclusion is obtained based on an enhanced approach. The proposed multiscale material model is incorporated into ABAQUS, and its effectiveness and robustness are documented by the simulations of unit cells containing aggregates of different shapes.