Homogenization-based modelling of reinforced concrete in the context of durability-oriented analyses

In the context of a poromechanics framework developed for durability-oriented analysis, the paper is mainly concerned with a constitutive model for reinforced concrete. A continuous concrete matrix and two different sets of steel reinforcement characterize the three-phase composite material. For each phase, the nonlinear pre- and post-peak behavior is described separately, while considering interactions between the reinforcement bars and the concrete. The material behaviour of the matrix material is formulated by a combined multisurface elasto-plastic damage model. A classical J 2 -plasticity flow rule describes the elasto-plastic response of the steel reinforcement. Based on continuum micromechanics, the Mori-Tanaka homogenization technique is considered as a suitable approach to derive the homogenized (macromechanical) constitutive relations of the composite material and related local (micromechanical) field information which is essential for durability analyses. Dowel action between the reinforcement bars and the concrete is implicitly captured by the chosen approach. The model performance is demonstrated by selected numerical and experimental studies.