Bridge Expansion Joint for Bridges with Precast Deck Panels

Precast concrete deck panels are increasingly used for accelerated bridge construction (ABC) to reduce construction time and traffic disruption. The expansion joint design for bridges with precast deck panels must address both the joints between adjacent panels and the expansion joints at the bridge ends. Full-depth precast deck panels are cast in a factory and installed on the bridge girders in a single operation. The panels are connected to each other by closure pours or mechanical connections at the transverse joints between panels. The expansion joint at the bridge end must be designed to accommodate the movement of the full-length deck. Transverse joints between precast deck panels are not expansion joints but must be designed to transfer loads between adjacent panels. The joint must be designed for the shear and moment transfer required to achieve composite action between the deck and the girders. Grouted shear keys or closure pours are the standard connection methods. Expansion joint installation at the bridge ends of precast deck panel bridges must be coordinated with the panel installation sequence. The expansion joint is typically installed after all panels are in place and the transverse joints have been grouted. The joint gap is set for the temperature at the time of installation. Differential camber between adjacent precast deck panels can create steps at the transverse joints that affect ride quality. The panels must be designed and manufactured to minimize differential camber. Any remaining differential camber must be corrected by grinding or shimming before the wearing surface is applied. Quality control for precast deck panel bridges requires careful inspection of the panel-to-panel joints and the expansion joint installation. The transverse joint grouting must be inspected for voids and proper curing. The expansion joint gap must be verified against the design value at the installation temperature. Any defects must be corrected before the bridge is opened to traffic.