Strategies to increase the robustness of endplate beam–column connections in fire

Numerical study results are present to demonstrate strategies to increase the robustness of endplate beam–column connections at elevated temperatures in a fire. Proposed strategies include increasing the bolt grade or diameter, adopting dog-bone shaped beam, channel endplate or spaced endplate connections. Numerical results show that adopting different endplate connection types (extended end plate, flush endplate, and flexible endplate) or increasing the bolt load baring capacity (increase its grade or diameter) only have very limited effects to increase the robustness of the connection during catenary stages of the framed beam in a fire. Appropriate treatment of the endplate or the steel beam can achieve satisfactory consequences. The adoption of either dog-bone shaped beam, bolted channel extended endplate or spaced extended endplate connection can increase the robustness of connection, which allows the connection to survive over 100 °C higher in critical temperature.

► Robustness of beam–column connection cannot be increased by using strong bolts.
► Novel methods to increase robustness of the connection in a fire are presented.
► Dog-bone shaped beam can delay the failure time of bolts in a fire.
► Bolted channel and spaced endplate can increase robustness of the connection.