Abstract: To promote the application of glass fiber-reinforced polymer (GFRP) in the civil engineering industry, this study conducted tensile tests on bolted-bonded hybrid joints using a brittle adhesive and two flexible adhesives with different tensile modulus and strengths, exploring joint performance under varying overlap lengths and adhesive thicknesses. The results show that among the three adhesives, the flexible adhesive with high modulus and high strength exhibited the highest load-bearing capacity. With increasing overlap length, the load-bearing capacity of mixed joints for all three adhesives increased. As adhesive thickness increased, the capacity of brittle adhesive joints decreased, while that of low modulus, low strength flexible adhesive increased. The flexible adhesive with high modulus and high strength achieved the best load-bearing capacity at an intermediate thickness of 1.0 mm. The low modulus, low strength flexible adhesive enabled combined bolted-bonded load sharing at thicknesses of 1.0 mm and 1.5 mm, whereas the other two adhesives could not achieve such synergy, exhibiting segmented brittle load-bearing characteristics during the loading process. The failure modes of the joints for all three adhesives were predominantly shear and splitting failure of the GFRP plates. This study provides a reference for future engineering practice.

Key words: adhesives, GFRP, bonded-bolted hybrid joints, tensile performance, experimental study