Engelhardt, Michael D.Williamson, Eric B., 1968-2016-10-192018-01-222016-10-192018-01-222016-08August 201http://hdl.handle.net/2152/41752Many older bridges in Texas are constructed with floor systems consisting of a concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders using post-installed shear connectors to change the behavior of the beam from non-composite to partially-composite. Since fatigue is one of the main concerns in designing bridges, investigating the fatigue properties of these post-installed shear connectors becomes crucial. Results from direct-shear testing show that post-installed shear connectors have a better fatigue life compared to conventional welded shear studs. However, based on currently available data from direct-shear tests, fatigue life of post-installed shear connectors is still inadequate for economical retrofit in some cases. Furthermore, it is unclear if direct-shear tests provide an appropriate means of evaluating fatigue performance. The objective of this dissertation is to develop new and more accurate approaches for evaluating the fatigue characteristics of post-installed shear connectors. This objective is addressed through large-scale beam fatigue tests and computational studies. The focus of the work is on evaluating fatigue life of shear connectors based on both slip and stress demands.application/pdfenFatigueShear connectorBridgeSteelCompositeNon-compositePartially-compositePost-installedRetrofitStrengthenSlipLarge-scaleUT slipMethodologyCheckContinuousGirderBehaviorExperimentalNumericalComputationalThesis2016-10-19