Shear strength of high-strength bolts at elevated temperature

Failure of bolted connections has frequently occurred during fire events. Because knowledge of the behavior of high-strength bolts while under fire is insufficient, there is further need to establish the behavior of high-strength bolt while under fire load. In this study, the behavior of high-strength bolts was investigated by a series of tests conducted at elevated temperatures with the parameters of temperature, number of bolts and the joint geometry analyzed. The strength deterioration and the deformation characteristics of the bolts were analyzed and discussed. Based on the experimental results, it was found that AIJ specification provides a conservative prediction for the strength of high-strength bolt under fire conditions, while BS5950 overestimated bolt strength. Eurocode 3 gave a good prediction on bolt strength.

► The behavior of high-strength bolt is evaluated under fire condition.
► The effects of temperature, bolt number and the joint geometry on the behavior of high-strength bolts are analyzed.
► Eurocode 3 gives a good prediction on bolt strength.
► AIJ provides a conservative prediction on bolt strength.
► BS5950 overestimates bolt strength.