Impact characterization of basalt fiber reinforced geopolymeric concrete using a 100-mm-diameter split Hopkinson pressure bar

Industrial wastes, slag and fly ash, were used to produce geopolymeric concrete (GC), and which was reinforced with short basalt fiber. Impact mechanical properties of basalt fiber reinforced geopolymeric concrete (BFRGC) of three different matrix strengths were investigated using a 100-mm-diameter split Hopkinson pressure bar (SHPB), and strain rate effects on dynamic compressive strength, critical strain and specific energy absorption were studied. For the valid SHPB tests on BFRGC specimens, the improved pulse shaping techniques were proposed to obtain dynamic stress equilibrium and nearly constant strain rate loading over most of test durations. The results show that impact properties of BFRGC exhibit strong strain rate dependency, and increase approximately linearly with strain rate. The transition point from low strain rate sensitivity to high sensitivity decreases with the increase of matrix strength. The addition of basalt fiber can significantly improve deformation and energy absorption properties of GC, while there is no notable enhancement in dynamic compressive strength. Increase of matrix strength results in decrease of deformation capacity and increase of energy absorption capacity for BFRGC.