Bond Assessment of GFRP Bars Embedded in Fiber-Reinforced Eco-concrete

Steel corrosion is a major problem in the civil engineering industry, thus finding an effective alternative has been of main interest. One of these alternatives is glass fiber-reinforced polymer (GFRP) bar, as it has multiple advantages including: corrosion-free, nonconductive, and high strength-to-weight ratio. On the other hand, conventional concrete (CC) is not environment-friendly concrete due to its high CO2 emission. Therefore, other replacements of Portland cement have been on the lookout. Some of the alternatives include fly ash and silica fume that can be added either partially or fully to make the concrete. In addition, adding fibers to the concrete has been of main interest, as it offers several advantages including crack control, and tensile capacity increase. In this study, a bond investigation was carried out using a pullout experiment to assess the bond-slip behavior between GFRP bars and fiber-reinforced eco-concrete (High-volume fly ash (HVFA) concrete) following the RILEM recommendations. The bond test was used owing to its structural significance and the lack of bond studies between such two sustainable materials (GFRP bar and HVFA concrete). The parameters of the study involved: concrete type (CC and HVFA), fiber type (steel and synthetic), bar type (GFRP and steel), bar size (13 and 19 mm), and embedment length (6.4 mm, and 12.7 mm). To make the assessment, the bond results of the GFRP-reinforced specimens were compared to those resulted from steel-reinforced specimens. The test results showed that the bond strength of GFRP bar was less than that of steel bar. Also, the addition of fibers to the concrete decreased the bond strength.