Bond Performance between Fiber-Wrapped Ribbed Basalt Fiber-Reinforced Polymer Bars and Seawater Sea-Sand Concrete

Abstract

The high corrosion resistance of fiber-reinforced polymers (FRPs) and related concrete structures means that they are suitable for application in the marine environment. Therefore, the replacement of steel bars with fiber-reinforced polymer (FRP) bars enhances corrosion resistance in seawater sea-sand concrete (SSC) structures. Geometric parameters significantly influence the performance of the bond between ribbed FRP bars and SSC, thereby affecting the mechanical properties of the concrete structures. In this study, the performance of the bond between ribbed (i.e., with fiber wrapping) basalt-fiber-reinforced polymer (BFRP) bars and SSC was investigated through pull-out tests that considered rib geometry and SSC strength. The results demonstrated that an increase in rib and dent widths reduced the bond stiffness, while an increase in rib height and SSC strength gradually increased the bond stiffness and strength. Additionally, the bond stiffness and bond strength were relatively low because the surface fiber bundles buffered the mechanical interlocking force between the BFRP ribs and the concrete, resulting in plastic bond failure during the loading process. Furthermore, the adhesion of the fiber bundles to the surface of the BFRP bars also influenced bond performance, with higher adhesion leading to greater bond stiffness and strength.