Modelling of the fully coupled chemo-mechanical degradation for cement-based materials

Abstract

The coupling of chemically induced degradation and mechanical damage is fundamental to investigate the durability of load-bearing cement-based materials subject to aggressive environments. This study is devoted to the incorporation of a reactive transport model and non-local damage model to integrate the complete process of chemical degradation and appropriate propagation of mechanical damage in the framework of coupled chemo-mechanical degradation. The chemical degradation of cement-based materials subject to leaching solution is principally concluded as the dissolution of portlandite and decalcification of C–S–H, and the reduction of Young's modulus is evaluated based on the microstructure of cement-based materials by the Mori–Tanaka scheme. The displacement-based non-local damage model is incorporated to capture the post-peak behaviour of the leached mortar beam in three-point bending test. The significance of coupling chemical and mechanical damage for the degraded beam is demonstrated by comparing the fully coupled damage with outcomes of the non-coupled case.