EXPERIMENTAL INVESTIGATION OF THE BEHAVIOUR OF FLUSH ENDPLATE CONNECTIONS IN FIRE

This paper reports a set of test results on flush endplate connections at ambient and elevated temperatures. This set of tests was aimed to investigate mainly the behaviour of connections at the ends of unprotected beams in fire situations, and may be subjected to significant tying forces and large rotations at high temperatures as a consequence of the beam deflection. Observed failure types in the tests tended to change the failing component from the endplate to the bolts with increase of temperature, as the bolt strength reduces faster than that of steel in fire. Most of the tested connections reached their maximum resistance at about 2° of rotation, and were then able to maintain a moderate amount of resistance up to a rotation of 7°, irrespective of their failure mode. At elevated temperatures, the use of thick endplates can enhance the peak resistance, but reduces the rotational capacity of the connection.