Jointless Bridge Deck with Link Slabs

Link slabs are used over the piers developing jointless decks while adjacent bridge spans remain simply supported. The Michigan Department of Transportation incorporates link slabs during deck replacements and deep resurfacing. Field performance assessment documented full-depth cracking of most of the link slabs. These cracks allow surface water infiltration, which leads to accelerated deterioration. This study was conducted to address link slab design and performance issues. The literature is inconsistent with the influence of design parameters on link slab performance. The objective was to document the link slab behavior of its design parameters, to propose a method to calculate the link slab moment and axial force, and to propose recommendations for updating current design details and construction procedures. Single-girder, two-span, finite element assemblage models under various types and levels of loads in conjunction with the link slab design parameters were used to evaluate the moments and axial forces developed in the link slab. Analysis showed that support conditions underneath the link slab greatly influence the link slab moment and axial force. Use of moment interaction diagram is recommended for the design. A detailed analysis and design example is presented incorporating live load, temperature gradient load, and the support configurations.