Blast responses of concrete beams reinforced with GFRP bars: Experimental research and equivalent static analysis

The glass fiber reinforced polymer (GRFP) bars have advantages in corrosion resistance and high load bearing capacity. They can be used as reinforcements in concrete protective structures to replace the steel bars. In this paper, the GRFP bar reinforced concrete beams (GRCBs) were designed, casted and tested. As a reference, the steel bar reinforced concrete beams (SRCBs) having the same flexural rigidity with the GRCBs were also designed, casted and tested. Under close-in explosions, the GRCBs have smaller displacement than the SRCBs, because the GFRP bars are still in elastic state while the steel bars enter into plastic deformation. Cracks, spalling and cratering are the main damage modes of the concrete beams. Through the quasi-static four-point-bending experiments, the residual load capacity of each beam has been evaluated, which quantitatively reveals the damage degree of the exploded concrete beams. In current research the explosion produces negligible damage to the GRCBs, while the load capacity the SRCBs reduces at a level of 28% at the most. The research proves that the GRCB has greater blast-resistance.