In this thesis, two major aspects of shotcrete are investigated through experimental studies. The first is the rebound characterstics of shotcrete, which has a significant impact on the construction cost. The second is the strength properties of shotcrete, which are somewhat different those of normal concrete, as the shotcrete generally contains accelerator in order to develop high strength at the early stage.
Amounts of rebound are measured for different shooting conditions as well as mix designs, so as to determine the optimal conditions. Strength tests are carried out using core samples taken from the specially prepared shotcrete molds with different mix designs such as cement content, accelerator dosage and sand aggregate ratio. In order to investigate the elastic properties of shotcrete, axial and lateral deformations of several selected specimens are measured using strain gauges. P-wave impact tests are also performed to measure dynamic modulus of shotcrete.
