Experimental study and statistical analysis of lean iron ore concrete with high impact resistance

Impact tests were conducted using a specially made drop hammer impact device on concrete specimens (C60–C90) containing lean iron ore from mine waste as coarse aggregate to realize enhanced impact resistance in applications such as pile driving. Impact resistance tests were also conducted on equivalent conventional limestone concrete specimens for comparison. The statistical analysis results show that the number of impacts at the initial and final cracking of lean iron ore concrete conformed to the Weibull distribution of the strength grade. The impact resistance of lean iron ore concrete was ~0.65–2.03 times greater than that of conventional limestone concrete. In this study, as the impact fracture energies of the C80 and C90 specimens were the maximum and the damage to the lean iron ore aggregate was obvious, the properties of the lean iron ore were completely utilized. Consequently, a linear relationship between the failure resistance of lean iron ore concrete and its strength grade was identified. Finally, the use of lean iron ore as a coarse aggregate in concrete was shown to effectively reduce the probability of the precast concrete pile head bursting during driving.