Mechanical properties and failure mechanism analysis of basalt-glass fibers hybrid FRP composite bars

In order to solve the defect of insufficient performance of the single fiber reinforced plastic (FRP) bars. The basalt fibers and glass fibers are prepared into the basalt-glass fibers hybrid FRP composite bars (B/G hybrid FRP bars) in this paper. The failure mechanism of basalt-glass fibers hybrid FRP composite bars is analyzed by the finite element method. The main failure factors include not only fiber breakage but also the separation of the interface between the two fibers. The mechanical properties of basalt-glass fibers hybrid FRP composite bars in the alkaline environment are predicted by simulation. The tensile properties, elongation properties, pseudo ductility stage length, and yield stress reduction of basalt-glass fibers hybrid FRP composite bars under different fiber volume ratios are investigated by tensile tests. The results show that when the volume ratio of glass fiber to basalt fiber is 7:3, the ultimate strain reaches 2.57%. When the volume ratio of glass fiber to basalt fiber is 9:1, the ultimate strain reaches 3.06%, with a difference of 0.49%. In addition, the yield stress reduction stage in basalt-glass fibers hybrid FRP composite bars is also affected by the volume ratio of hybrid fibers. When the volume ratio of glass fibers to basalt fibers is 9:1 and 7:3, the difference in ultimate tensile strength and the difference in yield stress reduction stage of the two are 185.85 MPa and 145.09 MPa, respectively. In addition, the optimal volume ratio range suitable for different situations is summarized in the study. When glass fiber accounts for 68.9–100% of the total integral number of basalt-glass fibers hybrid FRP composite bars, the tensile and extension properties of basalt-glass fibers hybrid FRP composite bars have different degrees of change.