Comparative Evaluation of Flexural Toughness of Steel Fiber-Reinforced Concrete Beams

Specifications are available to quantify flexural performance of steel-fiber reinforced concrete beams with several parameters. Each specification provides different results. This study comparatively evaluates existing flexural beam test standards that are used to evaluate the flexural toughness of SFRC beam specimens. Two standards, EN-14651 and ASTM C1609, were followed to test SFRC beams under the three-point bending test (3PBT) and the four-point bending test (4PBT), respectively. Both normal tensile strength steel fiber (1200 MPa) and high tensile strength steel fiber (1500 MPa) in high-strength concrete were considered in this study. The reference parameters recommended in the two standards, which include equivalent flexural strength, residual strength, energy absorption capacity, and flexural toughness, were compared based on the tensile strength (normal or high) of the steel fiber in high-strength concrete. The 3PBT and 4PBT results indicate that both standard test methods yield similar results to quantify the flexural performance of SFRC specimens. However, unintended failure modes were observed for both standard test methods. The adopted correlation model shows that the flexural performance of SFRC is similar for 3PBTs and 4PBTs, but the residual strength obtained from the 3PBTs tends to be greater than that obtained from 4PBTs with an increase in the tensile strength of steel fiber.