Influences on Shotcrete Rebound from Walls with Random Roughness

Table 1

Orthogonal design parameters.

Factor	Level
Surface tension (mN/m)	6.3, 8, 10.5
Viscosity (mPa.s)	53, 97, 135
Roughness (Ra, µm)	0.5, 1.5, 2.5
Velocity (m/s)	1, 2, 4