JOINT PERFORMANCE OF ALUMINUM–MAGNESIUM ALLOY-COATED HIGH-STRENGTH BOLTED FRICTIONAL GFRP JOINTS

This study experimentally investigated the effects of surface treatment, base-plate thickness, and splice-plate material on the joint performance and relaxation characteristics of high-strength bolted frictional glass fiber-reinforced polymer (GFRP) joints that utilize Al–Mg alloy-coated splice-plates, with a focus on corrosion and rust prevention. The tensile experiment results indicated that the slip coefficient was approximately 0.37 when the Al–Mg alloy coating was applied, whereas it decreased by approximately 10% when the GFRP was left uncoated. Moreover, in cases where SUS304 and SM400A underwent blast treatment, the slip coefficient exceeded 0.5; however, for thin GFRP plates, material failure occurred as soon as the slipping load was reached that resulted in a major load reduction. Additionally, relaxation tests on joints with Al–Mg alloy coatings revealed an approximate 25% decrease in axial force over 11 months post-tightening.