Page 25

2013FallShotcreteEMag

Technical Tip velocity is reached along the spray axis—that is, mph (35 m/s) with the double-bubble nozzle (dry), the centerline—and reduces gradually toward the decreasing gradually to 44.7 mph (20 m/s) at the edges of the spray. More precisely, centerline spray edges. In the wet-mix case, velocity distri- velocities obtained in dry- and wet-mix shotcrete bution is more uniform; the velocity difference is are respectively about 1.75 and 1.32 times higher lower with a centerline velocity equal to 73.8 mph than the velocities measured at the spray edges. (33 m/s) and an edge velocity of 55.9 mph The maximum centerline velocity is about 78.3 (25 m/s). The nozzle type and process can explain Fig. 3: High-speed camera ready to film a shotcrete spray Fig. 4: Particle tracking performed using image analysis software (Jolin and Ginouse 2012) Shotcrete • Fall 2013 23


2013FallShotcreteEMag
To see the actual publication please follow the link above