Durability of the Grouted Shear Stud Connection at Low Temperatures

This research proposal addresses the design and behavior of a new, recently developed connection for steel bridge substructures. This new connection, termed the grouted shear stud connection (GSS), was shown to be an effective and improved design over current practice of directly welding hollow circular steel pipe piles to steel cap beams. In previous studies, the new connection performed well, in both quasi-static and dynamic tests at ambient (indoor) laboratory temperatures. Because this new connection relies upon the integrity of grout, a cementitious material prone to degradation from severe environmental conditions typical in Alaska, the durability of this material and the connection as a whole must be assessed. This proposed project focuses on the durability of the GSS by optimizing the grout properties through material testing, and subsequent tests of weathered and unweathered full-scale connection specimens when subjected to temperatures as low as -40° C. The outcome of this research will be a set of design recommendations to maximize the durability and hence the long term performance of the grouted shear stud connection. While developed for new bridge construction, the GSS connection is readily adapted to retrofit applications in existing steel bridge substructures with deficient pipe column to cap beam connections. The results of this study may therefore be of value in the eventual structural upgrade of Bridge No. 455, the Anchorage Port Access.