Traditionally steel and composite steel and concrete beam to column joints
at the fire limit state are assumed to behave in the same way as used in th
e design at ambient temperature, that is a joint that is assumed to be pinn
ed at ambient temperature is also assumed to be pinned at elevated temperat
ures. Recent fire rests on the eight-storey steel frame building at Carding
ton suggest that joints, which are assumed to be pinned at ambient temperat
ure, can provide significant levels of both strength and stiffness at eleva
ted temperature. In steel structures, the behaviour of joints, between beam
s and columns may be investigated by separate consideration of the various
components. which comprise the joint. However, measurement of the distorted
profiles of components can be problematic. This paper describes thr use of
an image acquisition and processing technique for the measurement of defor
mations in steel T-stub connections, representing the tension component in
a steel joint. Although the application has been developed to solve the pro
blems associated with measuring deformations in tests conducted at high tem
peratures, it also offers advantages over conventional techniques at ambien
t temperatures. (C) 2001 Elsevier Science Ltd. All rights reserved.