Post-fire residual slip resistance and shear capacity of high-strength bolted connection

摘要

High-strength bolted connection is one of the main connecting forms of steel structure and its post-fire residual mechanical properties are important basis for post-fire evaluation and recovery of steel structure performance. This paper made an experimental study on slip resistance and shear behaviors of common engineering 8.8 s and 10.9 s high-strength bolted connection after high temperature, getting the load-displacement curves of high-strength bolted connection under different firing temperatures and cooling modes. The post-fire slip resistance and shear capacity of high-strength bolted connection were analyzed. Based on analysis of test data, it is found that post-fire slip resistance and shear capacity of high-strength bolted connection generally declined with the increase of the firing temperature. When the firing temperature is lower than 600 degrees C, slip resistance and shear capacity of high-strength bolted connection were similar with those under room temperature. However, when the firing temperature exceeds 600 degrees C, they declined quickly. The reduction factors of slip resistance and shear capacity at 900 degrees C reduced to about 035 and 0.75, respectively. The cooling mode could influence post-fire slip resistance and shear behaviors of bolted connection to a certain extent, but no explicit law was discovered, which needs further deep researches. Finally, the prediction formula concerning the reduction factors of post fire slip resistance and shear capacity of high-strength bolted connection was proposed based on test data fitting, providing certain references for evaluation of post-fire residual performance and recovery of steel structures. (C) 2017 Elsevier Ltd. All rights reserved.