Abstract:To elucidate the interfacial bonding mechanism between basalt fiber grid and concrete, the influence of yarn number and orientation, embedment depth, and polymer type was studied by pull-out test. The results indicate that the bond strength of epoxy resin impregnated grid (BE5) can be increased by more than 46.5% with the increase of the number of yarns due to its strong mechanical anchorage provided by grid joints. In contrast, the bond strength improvements of acrylic emulsion–impregnated (BS5) and polyvinyl chloride emulsion–impregnated (BO25) grids remain limited with increasing yarn number, owing to their weaker anchoring capacity. Grids in the warp direction exhibit higher bond strength due to the twisted yarn configuration, whereas weft-direction grids demonstrate greater pull-out work as a result of a larger effective bonding area and enhanced slip capacity. By comparison, it was found that BE5 formed a "strong yarn bundle-strong joint" bonding system due to the high permeability and crosslinking density of epoxy resin, achieving bond strengths 3.63 and 8.23 times those of BS5 and BO25, respectively, with a critical embedment depth of less than 9 mm. Micromechanical analysis confirms that superior interfacial performance depends on complete polymer penetration into fiber bundles for uniform stress transfer and adequate consolidation at the joints for effective mechanical interlocking.
