Abstract
It has been confirmed that bonding steel plates to GFRP plates for reinforcement improves joint strength and enables the application of high-strength bolted frictional joints. However, due to the creep characteristics of GFRP, the axial force of bolts decreases over time, which becomes particularly pronounced at high temperatures. Therefore, in this study, as a countermeasure against the creep of GFRP plates, we attempted to suppress the decrease in bolt axial force by enlarging the bolt holes in the GFRP plates to the diameter of the washers and inserting circular steel plates with the same diameter as the bolt holes. The temporal changes in bolt axial force were examined through temperature variation tests using a low-temperature constant temperature and humidity chamber, and the joint strength was evaluated through tensile tests of the high-strength bolted frictional joints. The results confirmed that while maintaining sufficient joint strength, it is possible to suppress the decrease in axial force at high temperatures. On the other hand, it was found that the decrease in axial force at low temperatures is greater compared to the conventional joint method.
