Experimental behaviour of end plate connections reinforced with bolted backing angles

A new method of providing local column flange reinforcement in end plate connections, using rolled steel angle sections, has been developed. The angles are bolted to the flanges and web of the column, adjacent to the incoming beam tension flange. A series of fifteen hybrid T-stub tests, incorporating an equivalent depth of beam web and with compression zone constraint, were carried out in order to determine the performance of connections reinforced in this way. The number of tests was chosen to include extreme reinforcement options for bolted backing angles as well as more practical cases. A special loading frame was designed and fabricated which satisfied the requirements of the tests. Connection strength improvements in the order of 200% were observed using angle reinforcement, compared with less than 40% using conventional welded stiffeners. The validity of using hybrid T-stubs for connection representation was confirmed by comparison with two conventional cruciform connection tests. (C) 1999 Elsevier Science Ltd. All rights reserved.