About the research
The objectives of this project were to validate design assumptions and evaluate the performance of the structural components and construction approaches provided in the design documents for a pretensioned, prestressed concrete beam-supported partial-depth precast deck system with cantilever precast overhang panels.
To achieve the objectives, laboratory tests were conducted on two small-scale specimens with horizontal loading on the barrier and vertical loading at various locations of the deck panels. The deck of each specimen generally consisted of two precast, cantilever overhangs, two precast, prestressed interior panels, and a portion of the cast-in-place (CIP) concrete deck.
The specimen details and construction work were carefully documented. The results indicated that the high-density polyethylene foam has sufficient stiffness and strength to support the precast deck panels and the construction load during concrete placement of the deck. The leveling bolt with normal polyethylene foam worked fine to support the deck panel and to resist the lateral concrete load. However, special attention during the gluing of the polyethylene foam is needed to ensure a good bond between the girder/deck concrete surface and the polyethylene foam.
The load test results indicated that both types of interior panels have an ultimate load capacity of about 240 to 250 kips when subjected to point load causing punching shear failure, exceeding the demands of the bridge service life. The composite action between the CIP and precast deck concrete is functional through the load application process, and no debonding or sliding was found at the horizontal interface between the CIP and precast concrete.