Linear and Non-Linear Cyclic-Creep of Concrete with defined Moisture Contents

• Applicants: Professor Dr.-Ing. Steffen Anders; Professor Dr.-Ing. Ludger Lohaus
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 399508601

Deformation measurements of reinforced concrete bridges have shown that the measured actual deformations significantly exceed the deformations calculated during design. One important reason is that the existing creep models neither take into account the cyclic nature of mechanical stresses nor the different moisture contents inside the concrete. Therefore, the aim of the joint-project at the Karlsruhe Institute of Technology, the Leibniz University in Hannover and the Bergische Universität Wuppertal is to develop a generalized model for the long-term deformation that takes the cyclic nature of the loading and the moisture content of concrete into account. The ranges of linear and non-linear creep deformations are covered. These extensive experiments are the basis for generalization of existing rheological creep models. For an improvement of the model and for a better understanding of the underlying mechanisms differentdeformations will be split up into the following parts: elastic deformations, delayed-elastic deformations as well as irreversible creep. The irreversible deformations will be further split up into creep with and without changes in structure such as micro-cracking. The aim is to provide an enhanced and generalized model for the prediction of the long-term deformations of concrete that takes into account the cyclic nature of the loading as well as the moistureconditions within the concrete.

• DFG Programme: Research Grants