Behavior of high-strength concrete columns subjected to blast loading

This paper presents the current analytical investigation at the University of Melbourne on the behavior of high-strength concrete (HSC) columns subjected to severe blast loadings. The variables considered were the magnitude of the blast, the concrete strength (40 MPa for normal strength concrete and 80 MPa for HSC). A constitutive law to model the strain-rate-dependent engineering properties of HSC is proposed. Dynamic stressstrain relations which differ considerably from the corresponding static relations are derived for the investigated load histories and are modeled with the proposed dynamic constitutive law. The effects of reinforcement detailing, geometry, and loading conditions on the dynamic behaviour of high-strength concrete columns were investigated by the Finite Element Explicit code LS-DYNA3D. A case study was carried out to assess the performance of a ground floor RC column of a typical office building under a bomb blast. It was found that HSC columns perform better than NSC columns (with the same axial load capacity) when subjected to extreme impulsive loading.