Concepts for Durable Post-Tensioned Bridges over Highways in Ontario, Canada

Cast-in-place post-tensioned concrete bridges present certain advantages over slab-on-girder bridges and they make up 20% of the Ontario Ministry of Transportation’s bridge inventory. Despite their excellent performance, relatively few are currently built. This paper presents two concepts for cast-in-place post-tensioned concrete bridge replacements over existing highways which overcome some perceived shortcomings. The first concept is two-span cast-in-place voided slab underpass with monolithic pier columns and integral abutments on caissons. The superstructure is cast 1.2 m above the final profile to allow for falsework clearance over three lanes of highway in each direction, and jacked down to the final alignment. The second concept is a single-cell box girder underpass with two spans of 37.5 m, monolithic pier column, and integral abutments.