Response of high-strength concrete to dynamic compressive loading

•Enhancements to split Hopkinson pressure bar technique for testing high-strength concrete.•Rate sensitivity determined for HSCs; similar DIF values for C60 and C80, but a much lower DIF for C110.•CEB-FIP model (2010) is inadequate for estimating rate sensitivity for HSCs, especially C110.•FE simulation confirms that the rate dependence determined from dynamic tests represents actual material behaviour.•Influence of radial inertia on compressive strength obtained from SHPB tests was examined via FE simulation. An experimental investigation into the dynamic compressive response of high-strength concrete with three different strengths – 60MPa, 80MPa and 110MPa, denoted by C60, C80 and C110, respectively – was undertaken. Concrete specimens were subjected to quasi-static and dynamic compression, using a Denison Universal Testing Machine and a Split Hopkinson Pressure Bar (SHPB) device, and the effects of strain rate on their mechanical properties (e.g. stress-strain relationship, compressive strength) examined. Significant rate dependence was observed for all three concretes – i.e. the compressive strength increases with strain rate and the dynamic strength is much higher than the static value; C60 and C80 exhibited similar rate sensitivity, while C110 displayed a relatively noticeably lower rate dependence. The rate sensitivity was quantified via a Dynamic Increase Factor (DIF, the ratio between the dynamic and static strength), and this was compared with predictions by the CEB-FIP 2010 equation, commonly utilised to estimate rate sensitivity for normal strength concrete. The comparison indicates that the model is not suitable for high-strength concrete, as it predicts a sharper rise in rate-sensitivity, and the mismatch increases with concrete strength, becoming notably significant for C110. Interpretation of rate dependence of concrete materials based on SHPB test results, as to whether it is an intrinsic material property, or generated primarily by radial inertia, was examined by finite element modelling of SHPB tests. Concrete material properties were taken to correspond to a concrete damaged plasticity model, and the quasi-static stress-strain response, coupled with the Dynamic Increase Factor determined from dynamic tests, was utilised. The simulation results correlated closely with experiments, in terms of strain gauge signal histories in the SHPB loading bars, indicating that for the strain rate range investigated (30–110 s−1), radial inertia is not