Experimental Testing for Partial Height UHPC Beam End Encasement on Weathering Steel Bridges in Connecticut

Abstract

The use of Ultra-High Performance Concrete (UHPC) beam end encasement has proven to be a viable, cost-effective, and efficient method for rehabilitating corroded steel bridge girders compared to traditional replacement techniques. This method, developed jointly by the University of Connecticut and the Connecticut Department of Transportation (CTDOT), has been extensively researched over the course of seven years. The repair works by welding headed shear studs to intact portions of the web and encasing the beam end in UHPC, creating an alternate load path for bearing and shear forces. Recently, CTDOT has completed two repair implementations using this method, a full-height and partial-height repair, as part of the third phase of research. Full-height repairs employ a UHPC panel that spans the full depth of the web between the top and bottom flanges. In contrast, partial-height repairs are applicable for beams with section loss that is limited to the bottom of the web, with the UHPC panel extending only from the bottom flange to part of the way up the girder web. Following selection of a bridge for the partial-height implementation, additional experiments were conducted to evaluate design components that varied from previous research and implementations. This includes the application of the repair on weathering steel and the use of flange studs in addition to web studs. The results of these experiments confirmed the viability of the design and enabled the successful implementation of the second repair.