Creep and shrinkage at variable hygric exposures

• Applicant: Professor Dr.-Ing. Michael Haist, since 9/2019
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 327002599

The prediction of the shrinkage and creep behavior of structural concrete today is limited to constant loadings and constant environmental conditions. The influence of variations in the mechanical loading or the moisture conditions are neglected. Singular investigations in the literature however indicate a pronounced influence, eventually leading to safety risks for existing structures. The goal of the proposed research project carried out by the Universities of Wuppertal and Hannover and the Karlsruhe Institute of Technology is to quantify and model the effect of a combined mechanical and hygral variation in the creep loading. The proposal of the Karlsruhe Institute of Technology at hand hereby focusses on studying the influence of hygral variations on the concrete creep and shrinkage behavior. For this purpose, shrinkage and creep tests will be carried out on two concretes of different strength. The moisture content of the ambient climate during the tests will be varied in different steps and compared to measurements at constant climate. As from knowledge of the microstructure of concrete it is to be expected that the creep deformation will strongly depend both on the moisture content as well as on the moisture gradient in the sample, all samples will be subjected to a thorough pre-conditioning regime, in which both moisture content and gradient will be carefully adjusted in the samples. Combined with the results of the research partners at Hannover and Wuppertal a much more realistic understanding of the creep and shrinkage behavior of concrete will be obtained, leading to a significant improvement in deformation prediction models and eventually building safety.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr.-Ing. Harald S. Müller, until 9/2019