Impact Resistance and Ductility of Steel Fibre Reinforced Concrete Panels

Abstract

An experimental investigation has been conducted to study the impact resistance and ductility of simply-supported steel fibre reinforced (SFR) concrete square panels. Two series of panels, 50mm and 75mm thick, were manufactured with three distinct types of steel fibres. Within each series, two relatively low-volume fibre concentrations (0.5% and 1.0%) were adopted in the concrete mix. Repeated impact was provided by a freefalling hemispherical shaped steel projectile at the centre of the panels. For a given panel thickness, an empirical formula was used to calculate the critical height that would cause perforation. However, in order to study the influence of repeated impact, only 50% of the calculated critical height of each series of panels was used. After each impact, the deflections of the SFR concrete panels were measured and plotted. The nominal increase in thickness does not significantly improve the damage resistance and ductility of SFR concrete panels as tested. However, the fibre concentration and fibre type influence the impact resistance and ductility of SFR concrete panels. Calculated impact ductility and support rotation compared favourably with blast design data in a US Army manual. SFR concrete panels may be categorised according to the manual. The experimental results could be utilised to assess impact resistance of SFR concrete structures.