Micromechanical mechanisms of the time dependent deformation behavior of early-age concrete

• Applicant: Professor Dr.-Ing. Michael Haist
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: from 2016 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 310950436

The deformation behavior and the mechanical properties of concretes at early ages of hydration are only insufficiently understood, even though these properties play a central role in controlling the construction process as well as in the casting of damage-free structures. This deficit in knowledge is due to the highly dynamic transition of the microstructure of concrete during this phase, leading to substantial changes in the material deformation properties. Furthermore, measuring both the microstructural transition as well as the resulting changes in deformation behaviour is highly challenging. The aim of the proposal at hand is to identify the microstructural mechanisms of the deformation behavior of young pastes and concretes using experimental investigations to build up a model for this deformation behavior using micromechanics concepts. The results obtained in this study so far indicate, that these goals can be met (see progress report). However, the tests also showed certain ambiguity in the interpretation of the data, which is due to the fact that information on the local distribution of the microstructural phases is missing. Herefore, in the applied extension of the project, a chemical mapping of the surfaces of existing specimens shall be carried out and the chemical results shall be coupled with the corresponding mechanical data. Herefore, the applicant applies for an extension of his stay by 2 months.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr.-Ing. Franz-Josef Ulm