Training and Design Guidance for Using Ultra-High Performance Concrete for Bridge Deck Overlays

Research Team: Laura Melendy (lead) and Charles Sikorsky

UC Campus(es): UC Berkeley

Problem Statement: Increased and heavier traffic loads and harsh environmental conditions can seriously damage the deck surface of post-tensioned box-girder bridges. Since the deck plays an integral part in supporting the weight of these bridges, a special approach is required for repair, rehabilitation, or replacement of the deck. A recent UC Davis study that investigated various rehabilitation strategies determined a full-depth deck replacement approach can cause problems because it can produce compressive stresses in the web of the box girders that they were not designed to handle. Therefore, developing a cost-effective alternate means to improve the condition of California box-girder bridge decks and extend their service life is imperative. Laboratory and field tests conducted through a partnership between Iowa State University (ISU) and the Iowa Department of Transportation have demonstrated that bridge deck deterioration can be mitigated, thereby significantly increasing the lifespan of the decks, by using Ultra-High Performance Concrete (UHPC) as a deck overlay. ISU has developed a box-girder bridge deck rehabilitation method involving the partial removal of the existing concrete deck and its replacement with a UHPC layer with or without incorporating additional deck reinforcement.

Project Description: This project will develop an educational course to be taught to practicing engineers. First, previous work in other states to rehabilitate deck slabs on girder bridges will be presented, including an explanation of the challenges faced using ultra-high performance concrete. Then the findings from the previously mentioned research will be reviewed and recommended changes to Caltrans design guidance for rehabilitating post-tensioned box girder bridges will be explained. To demonstrate the methodology at least one design example will be provided showing how an existing bridge deck can be rehabilitated. Quality control recommendations and examples of best practices will also be provided. A set of lecture notes with examples will be provided.

Status: In Progress

Budget: $23,500