Strengthening Existing Non-Composite Steel Girder Bridges by the Use of Post-Installed Shear Connectors

A number of older bridges are constructed with floor systems that consist of a non-composite concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to use post-installed shear connectors to permit the development of composite action. This paper presents the results of a study examining ways to strengthen existing non-composite steel bridge girders using post-installed shear connectors. Five full-scale beams were tested to evaluate structural performance of composite beams retrofitted with post-installed shear connectors. Results of the study indicate that the addition of a relatively small number of post-installed shear connectors can increase the load capacity of non-composite girders by a factor greater than 1.5. As a result of this study, a design approach based on partial composite action was developed for strengthening existing steel bridge girders by using post-installed shear connectors.