“…Most of the data on connectors have been obtained from various types of push-out test. Since the 1960s, various researchers have conducted a great number of cyclic push-out tests to determine the fatigue life of shear connectors (Akao, Kurita, & Hiragi, 1982;Feldmann, Gesella, & Leffer, 2006;Feldmann, Hechler, Hegger, & Rauscher, 2008;Hanswille, Porsch, & Ustundag, 2007;Johnson, 2000;Leea, Shimb, & Changc, 2005;Nakajima et al, 2003;Oehlers, 1989;Slutter & Driscoll, 1965;Veljkovic & Johansson, 2006) Although safety factor in initial design may delay the occurrence of fatigue problems, the priori negligence of corrosion pits in structural integrity analysis may lead to significant overestimation of the damage tolerance ability of existing steel structures (Petroyiannis, Kermanidis, & Akid, 2005). There is lack of protection between the concrete slab and steel girder interface and also makes corrosion difficult to be detected.…”