An exploratory study of GFRP rebar with ribs containing milled glass fibers

Surface deformations of GFRP rebars are important in developing mechanical anchorage. The mixture of epoxy resin and milled glass fibers is considered as an alternative for surface structure of GFRP rebar to enhance the bond with the concrete. In order to investigate the applicability of the surface structure, manufacturing, material tests, pullout tests and shear tests were conducted. The mixture was successfully applied and shaped onto the GFRP rebars when the milled fibers were mixed to be within 20–50 wt% of the mixture. The bond performance was enhanced by adding as much milled glass fibers as possible but up to a workable range. When the milled glass fiber content was 50%, the upper limit of mix ratio, bond strength to concrete was only 10% less than that of the ordinary steel rebar. In addition, under an accelerated alkalinity condition, the amounts of mixed milled glass fibers in surface deformations have a minor effect on the durability of the proposed GFRP rebar.