Evolution of mechanical properties of steel fiber-reinforced rubberized concrete (FR-RC)

Abstract

In this work, the evolution of strength (compressive, tensile, and flexural) and toughness of steel fiber-reinforced rubberized concrete (FR-RC) with various fiber dosages and rubber contents was studied. The toughness of FR-RC was investigated using both four-point bending unnotched beams and three-point bending of notched beams. The toughness characteristics were quantified using toughness indexes proposed in ASTM C1018 and doubleK fracture model. The results show that the compressive strength of FR-RC is dependent on both rubber content and fiber dosage, while the flexural and tensile strengths are dominated by the fiber dosage. Although steel fiber can slightly increase the modulus of elasticity of FR-RC, it is mainly controlled by the rubber content. In addition, the first peak strength of FR-RC is influenced by both rubber and steel fiber inclusion, which is in agreement with its strength development. The steel fiber controls the straining hardening and softening behaviors of FR-RC. According to the double-K fracture model, it is found that the rubber content dominates the initial fracture toughness, while the steel fiber dominates the unstable fracture toughness.