Application of thermo-hydro-chemo-mechanical model for early age behaviour of concrete to experimental massive reinforced structures with strain-restraining system

摘要

This paper presents the application of a thermo-hydro-chemo-mechanical (THCM) model to the design of actual massive structures with a system to restrain the strain at early age (thermal strains and autogenous shrinkage). The experimental campaign was performed in the French national project CEOS.fr. The modelling of early-age behaviour of reinforced concrete is first based on a hydration model, which is able to reproduce the variations of temperature, water content and mechanical properties according to hydration. Then a non-linear mechanical model is used (combining creep and damage models, both adapted to hardening concrete). The comparison between numerical results (obtained with a calculation time of around 12 h on an ordinary computer) shows that the models are able to reproduce the early-age behaviour of restrained reinforcement concrete structures (in terms of strains, global forces and crack patterns). Using steel-concrete interface elements (adapted to early age), the models are also able to reproduce the influence of reinforcement on cracking.