Table 1.

Summary of material properties for the grains and blocks used in the impact tests.

Type	Material	Density (t/m3)	Poisson’s Ratio	Surface Roughness (nm)	E (GPa)
Block	Brass (N2)	8.50	0.35 β	50 *	100 β
	Granite	3.00	0.30 Λ	412 ± 35	86
	Rubber	1.50	0.50 ψ	270 ± 42	0.1
Grain	Glass (smooth) (2 mm)	2.60	0.30 #	95 ± 28	58 *
	Glass (smooth) (3 mm)			58 ± 18
	Glass (smooth) (4 mm)			67 ± 23
	Glass (rough) (3 mm)			387 ± 81	-

^# Gu and Yang [41], ^β Marinack et al. [32], ^Λ Gupta and Rao [39], ^ψ Holownia [40], * Sandeep and Senetakis [20].