Factors affecting the thermo-chemo-mechanical behaviour of massive concrete structures at early-age: Fid-Bau Portal

Factors affecting the thermo-chemo-mechanical behaviour of massive concrete structures at early-age

Honorio, Tulio / Bary, Benoit / Benboudjema, Farid

Abstract Different factors related to construction site conditions must be accounted for when designing concrete massive structures in order to accurately predict the cracking risks at early-age. Detailed descriptions of the thermal and mechanical boundary conditions as well as analyses accounting for the coupling between damage and creep may lead to computationally expensive simulations campaign. On the other hand, simplified modelling strategies have been extensively used but may not capture accurately key aspects of such analysis. Based on a previous chemo-thermal analysis by Honorio et al. (Eng Struct 80:173–188, 2014), the present study focuses on the mechanical behaviour of a specific structure by making use of a coupled thermo-chemo-creep-damage model. Simplified modelling strategies to treat the external restraints and some thermal boundary conditions are compared to more realistic ones. The risks of cracking are assessed by means of a cracking index (CI) and a damage model. Restraint conditions in which the ground is not represented leads to cracking risks in different zones if compared to the case with the ground. It is shown that, the ambient temperature affects directly the tensile stresses reached and the oscillation of the temperature within a day may play a non-negligible role. The effect of damage and its coupling with creep are analysed, and a strong influence of the corresponding coupling parameter on the cracking initiation and propagation is observed.