High Strain Rate Behaviour in Tension of Different Reinforcing Steels

Abstract

In their lifetime reinforced concrete structures can be exposed to severe dynamic loadings such as blast and impact. In this case concrete and reinforcing bars are subjected to high strain-rates. Although the dynamic behaviour of the reinforcing steel is of crucial importance in the structural assessment under the aforementioned conditions, only few researchers analysed this issue. The tensile high strain rate behaviour of the B500A, B500B, B450C and AISI304 reinforcing steels was studied by means of experiments carried out at 250, 500 and 1000s-1 using a Split Hopkinson Tensile Bar (SHTB). In the case of B500A steel, the specimens were coming from four different rebar having diameter of 6, 8, 10 and 12mm. For the B450C steel, considered as a composite bar made of a hardened outer layer, an intermediate hardened layer and a soft inner core, the effects of the strain rate on the mechanical properties in tension of these three layers were evaluated. Reinforcing steel specimens (coming from a rebar having a diameter of 12mm) of the B500B and AISI304 types were finally investigated at the same high strain rates. With the obtained data the parameters of the most common material constitutive relationships were determined.