Behaviour of Single and Double Row Bolted Shear Tab Connections and Weld Retrofits

The use of shear tabs continues to be one of the most popular methods of connecting steel beams to columns or girders. The current design procedure for shear tab connections in the 2010 CISC Handbook of Steel Construction is based on research conducted in the late 1980s. Some of the tabulated design values in the Handbook are based partly on outdated resistance factors and clauses. The CISC design method is also limited in its applicability; it applies only for shear tabs having a single row of seven bolts or less. Consequently, an up to date design procedure applicable to single and double row bolted shear tab connections featuring up to ten bolts per row is proposed by the author for use in Canada.;In order to gain a better understanding of the behaviour of shear tab connections, sixteen full-scale tests were conducted using three different sized test beams. Connections varied in size from one row of three bolts to two rows of ten bolts. Six bolted connections and ten retrofit weld tests were conducted as there was a demand for information on retrofit welds from the consulting engineering community. Shear tab weld retrofits are often performed on construction sites when members are damaged or when detailing errors cause misalignments between bolts and holes. The tests on weld retrofits shear tab connections sought to determine whether they possessed sufficient ductility to accommodate the rotation demand and to establish the loads that these welded connections could withstand. The weld retrofit connections did reach the targeted rotations and did resist at least the same loads as their corresponding bolted connections were predicted to resist. The welded and bolted connections behaved differently in terms of the onsets of flexural and shear yielding. This behaviour was consistent for all test beam sizes for both single and double row tests. Weld retrofit connections tended to outperform their bolted counterparts in double row tests. The opposite was true in single row tests.