Bond Behavior of Straight and Headed GFRP Bars Embedded in a Cementitious Composite Reinforced with Basalt Fiber Pellets

In this study, the bond behavior of sand-coated glass fiber-reinforced polymer (GFRP) bars embedded in a novel type of cementitious composite, containing nanosilica, slag, and reinforced with recently developed basalt fiber pellets (BPs), was evaluated. Steel fibers (SFs) were incorporated in control mixes for comparison purposes. Ninety-five cubic pullout specimens were prepared and tested according to Canadian standards. The test parameters were the type of cementitious composite, the bar diameter, the type of fibers, the dosage of BP, and the type of GFRP bar end. The bond performance was elucidated through the compressive strength of the composite and load-slip response of GFRP bars. In addition, the fiber bridging mechanism was determined by evaluating the residual bond strength and toughness indices. The provisions for bond strength in the Canadian and American codes were also assessed. The test results showed the effectiveness of the BP in enhancing the failure pullout load compared to counterpart specimens comprising SF, which makes them a good candidate for infrastructural applications including rehabilitation.