Hardening Induced Stresses in Very Thick Concrete Members - Insights from Comprehensive FE-Studies: insights from comprehensive FE-studies

This contribution presents first results of comprehensive FE-studies on hardening-induced stress histories of very thick concrete members with compact dimensions. The motivation is to improve the understanding of their structural behaviour in order to provide an efficient but safe crack width control of such members. The strict application of current design rules would lead to very high reinforcement amounts, even though observations in practice indicate that serviceability can be ensured with much less reinforcement. Finally, the insights of these investigations will provide a basis on which efficient design rules can be developed for very thick concrete members. The FE-studies were conducted with a new constitutive law for hardening concrete whereby special regard was put on the influence of the member thickness, the ambient temperature as well as production conditions. In general, the results confirm the predominance of residual stresses or so called Eigenstresses in such structural elements, while restraint forces and restraint moments are of minor importance for usual subsoil conditions.