PHYSICAL AND MECHANICAL-PROPERTIES OF STEEL FIBER-REINFORCED DRY-MIX SHOTCRETE

Dry-mix shotcrete reinforced with various contents of four different t ypes of steel fiber was tested to evaluate in situ fiber content, fibe r orientation and influence on mechanical properties, compressive and tensile strength, modulus of elasticity, and post-crack reinforcing ab ility. Theoretical models are proposed and rested to asses fiber loss and fiber orientation inside shotcrete. Results indicate that although dry-mix shotcrete has some very distinct characteristics compared to the cast concrete matrix [high cement content, w/c below 0.35, high vo id volume, tendency for fiber two-dimensional orientation (unknown in situ fiber content)], SFRS is somewhat similar to the unreinforced dry -mix shotcrete matrix with respect to mechanical properties up to the first crack. Alter this point, its reinforcing ability appears to be d ependent not only on fiber type and content but also on the set-accele rator admixture and fiber orientation.