Experimental investigation of bolted concrete column–foundation connections under lateral repeated loading

In this study, behavior of concrete column-foundation connections under repeated lateral loading was examined. Six column -foundation specimens were tested. The specimens consisted of one monolithic concrete column, three columns with the embedded stiffener connections, and two columns with the one-face welded (W1) connections (without stiffener). The stiffener connections were created by welding triangular plate to the longitudinal reinforcement and then welding them to the upper surface of the base plate, while in the W1 connections, the longitudinal reinforcement was welded directly to the upper face of the base plate. All specimens were similar in dimensions. The foundation measured 700 mm in length by 300 mm in width by 200 mm in thickness, and the columns a square cross section of 120mmx120mm with 700mm length. The study examined one of the most important factors affecting column foundations connection using steel base plates. The cyclic response of the specimens, such as failure load, failure type and lateral displacement histories, was examined under the effect of axial load of 80 kN. The experimental results showed that the columns using spatial stiffener connections were more resistant to lateral loads if compared to the W1 and monolithic column specimens under similar axial loading conditions.