Effects of single panel replacement on a full scale, full depth, precast concrete bridge system.

摘要

The use of precast concrete deck panels is becoming increasingly popular for bridge construction and rehabilitation in the state of Utah and across the country. It allows for the use of full depth concrete deck panels but removes the long construction times of traditional cast-in-place methods. One of the challenges to the use of precast deck panels is the transverse deck panel joints that exist between the panels. These joints are unreinforced using traditional methods and therefore are the weakest section of the bridge. In many situations the joint will fail and water seeps through and can damage the bridge superstructure.;Post-tensioning of precast decks has become the standard. The post-tensioning provides reinforcing through the joints, reducing the cracking that occurs. Additionally, the post-tensioning provides pressure along the joint and closes cracks that have occurred, therefore preventing water from leaking through to the superstructure and damaging it. The Utah Department of Transportation uses post-tensioning cables that run along the length of the bridge deck, applying pressure on the joints. One of the problems with using this method is it does not allow for the replacement of a single deck panel should the need arise. Utah State University has been researching a new post-tensioned connection that would allow for the replacement of a single deck panel. The "curved bolt" connection connects each deck panel to adjacent panels, providing reinforcement and post-tensioning along the joint. Laboratory testing was undertaken to investigate the effects of single panel bridge rehabilitation on the existing deck system.