Using the split Hopkinson pressure bar to investigate the dynamic behaviour of SFRC

Abstract

The dynamic characteristics of steel fibre reinforced concrete (SFRC) have been obtained through 75 mm diameter split Hopkinson pressure bar (SHPB) tests. In order to understand the intrinsic dynamic behaviour of the material, this paper reviews the SHPB testing technique, and presents the principles and limitations of the equipment. Using a linear-shaped striker bar, a half-sine incident loading waveform is generated which eliminates attendant problems such as non-uniform stress distribution and wave oscillation. Following the verification of the SHPB equipment, a number of dynamic uniaxial compression and tension splitting tests were conducted on SFRC specimens. The influence of strain rate on the response of SFRC specimens is presented. Results indicate that dynamic uniaxial compressive strength of SFRC increases moderately at relatively high strain rate, and the tensile splitting strength increases many times at moderate strain rate loading compared with its static value. Further, the stress–strain relationship of SFRC does not exhibit the ductility that is evident when the material is tested at static load condition.