| description abstract | Basalt fiber–reinforced polymer (BFRP) is widely used to reinforce concrete due to its high strength, lightweight nature, good corrosion resistance, and low cost. Previous studies have shown that the double-helix BFRP macrofiber has better bond behavior with concrete compared with other types of BFRP fibers. This is attributed to its irregular geometry. The bond-slip behavior between double-helix BFRP macrofiber and concrete is further numerically studied in this study. The corresponding finite-element model is established, and the accuracy of the numerical method is validated by the experimental results based on fiber-matrix pullout tests. The effects of twisted pitches, bundle numbers, and cross-section shapes of the fiber on the bond-slip behavior are extensively investigated and discussed. It is shown by the numerical results that the bond stress and energy-dissipating capacity increase with the decrease of twisted pitches (30, 20, 10, and 5 mm). The bond stress of the fiber with a twisted pitch of 5 mm can be increased by 17.0% at most compared with the fiber with a twisted pitch of 30 mm. Furthermore, it is found that the double-helix BFRP fiber has higher bond stress than the fiber with three or four bundles, with corresponding increases of 11.9% and 16.9%, respectively. | |
