Multi-physics numerical model for the repair of concrete structures

Experience has shown that repairs of concrete structures are often subject to premature cracking because the already dry and rigid substrate of the damaged structure contrasts the drying and self-drying contractions of the new material of restoration. In this paper a thermo-hygro-chemo-mechanical (THCM) model for concrete at early age is presented and used to analyze the behaviour of a real repair case taking into account casting and environmental conditions. The multi-physics mathematical model is a simplified version of COMES-HTC (developed a few years ago by Gawin, Pesavento & Schrefler, 2006). The THCM model for concrete at early age has been implemented in the French finite elements code CAST3M (developed by the CEA, Commissariat a l'Energie Atomique Francais).