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

Dry-mix shotcrete reinforced with various contents of four different types of steel fiber was tested to evaluate in situ fiber content, fiber orientation and influence on mechanical properties, compressive and tensile strength, modulus of elasticity, and post-crack reinforcing ability. 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 void 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 dependent not only on fiber type and content but also on the set-accelerator admixture and fiber orientation.