A repeated drop-weight impact testing apparatus for concrete

Abstract

Synopsis The development and use of a versatile instrumented repeated drop-weight impact testing apparatus for concrete is described. Impact resistance is determined in terms of the number of blows required to completely fracture steel-fibre-reinforced concrete test specimens. Parameters investigated included specimen geometry, notch depth, steel-fibre concentration, and mass and height of the dropped weight. Coefficients of variation of 15–20% were measured. Two load cells were used to monitor the impacting loads and the corresponding loads at the support, from which load-time graphs were plotted. Peak loads developed, impulsive loads and the duration of the impact event could then be measured. Good reproducibility was observed from the peak load results. The graphs also showed that larger masses were more efficient than lighter masses in producing impact failure in the test specimens.