An integrated experimental and computational study to the rate effect of concrete in tension

TNO and Delft University of Technology (DUT) have defined a joint research programme on impact dynamics of structures and materials. The behaviour of concrete under dynamic loading is one of the main research issues, while the combination of numerical simulation and experimental research is pursued and promoted.
At the previous ISIEMS conference an alternative SHB test methodology, based on the old principle of spalling, has been presented. The feasibility was demonstrated by the TNO prototype test set-up. Based on the results of the feasibility study and the promising perspectives, TNO decided to build a small and large scale test set-up. A combined numerical and experimental research programme was defined to study and understand the basic mechanisms that cause the rate effects in concrete and gain data on strength and fracture energy at loading rates up to 1000 GPa/s.
The current paper is an introduction to the research programme. It summarizes the state of the art knowledge on the basic rate effect mechanisms in concrete under uniaxial tensile loading. The outline of the research programme is given. The contribution of moisture contents to the observed rate effects, the concrete composition and the possibilities to model the physics numerically are key research issues. After the outline of the programme, the testing devices for static loading, dynamic loading at 10 GPa/s and the new set-up for loading rates at 1000 GPa/s are described. Finally, the paper addresses the results of the first test series and the development of a numerical model that includes the rate effect.