In-plane cyclic testing of precast concrete wall panels with grouted metal duct base connections

Abstract

In order to achieve satisfactory seismic performance the connections between precast concrete wall panels and other structural elements should be well-designed to avoid brittle connection failure during an earthquake. Following the 2010/2011 Canterbury (New Zealand) earthquakes it was observed that brittle failure had occurred in some grouted metal duct connections used for precast concrete wall panels, resulting in recommendations for more robust detailing of this connection type. A set of experimental tests was subsequently performed to investigate the in-plane seismic behaviour of both existing and newly recommended detailing for precast concrete wall panel connections, with this testing comprised of seven reversed cyclic in-plane tests of full-scale precast concrete wall panels having wall-to-foundation grouted metal duct connections. Walls with existing connection detailing were found to perform adequately when carrying low axial loads, but performance was found to be less satisfactory as the axial load and wall panel length increased. The use of transverse confinement reinforcement around the grouted metal ducts was observed to prevent brittle connection response and to improve the robustness of the reinforcement splice.