3D numerical modeling of damage and fracture due to Alkali-Silica Reaction in concrete structures

摘要

Modeling damage and cracks in a 3D concrete structure submitted to Alkali-Silica Reaction (ASR) is of prime importance in civil engineering. Concrete is considered as a heterogeneous material with three phases: aggregates, mortar and an interfacial zone between aggregates and mortar. This paper presents the model we have developed to understand the mechanical behavior of concrete submitted to this chemical reaction. We consider in this model concrete as a heterogeneous material with two main phases: the cement matrix and aggregates. The non local Mazars model has been successfully implemented in our finite element code Femcam to take into account the mechanical behavior of concrete. An application to a numerical concrete submitted to ASR is presented. Once damage has reached a critical value, macro cracks are initiated in the sample. The Discrete Crack Approach has been chosen for its good physical representation of crack propagation. An algorithm is presented and a validation on a three point bending test is performed. It shows also the great influence of heterogeneities on the crack path.