EXPERIMENTAL EVALUATION OF STRUCTURAL BEHAVIOR OF PRECAST UHPC WAFFLE BRIDGE DECK PANELS AND CONNECTIONS

摘要

The AASHTO strategic plan in 2005 identified extending the service life of bridges andaccelerating bridge construction as two of the grand challenges in bridge engineering. Themotivation behind these challenges was to produce safer, economical and minimal maintenancebridges with a service life of 75 years at a faster rate to cater the country‟s increasinginfrastructure needs. Previous studies have shown that a prefabricated full-depth precast concretedeck system is an innovative technique that accelerates the rehabilitation process of a bridgedeck, extending its service life with reduced user delays, and community disruptions and lowersits life-cycle costs. Also, the recent use of ultra high performance concrete (UHPC) in the UnitedStates for bridge applications have been proven to be efficient and economical due to its superiorstructural and durability characteristics and their potential to increase bridge longevity. Byadopting the advantages from the previous research on UHPC, the design of full depth UHPCwaffle deck panel system has been developed over the past three years in Europe and the UnitedStates.A full-scale, single span 60 ft long and 33 ft wide prototype bridge with full depthprefabricated UHPC waffle deck panels has been planned for a replacement bridge in WapelloCounty, Iowa. In support of this project, the structural performance characteristics and theconstructability of the UHPC waffle deck system and its critical connections were studiedthrough an experimental program at the structural laboratory of Iowa State University (ISU).Two prefabricated, full-depth, UHPC waffle deck (8ft x 9ft 9 inches x 8 inches) panels wereconnected to two, 24-ft long precast prestressed girders and the system was tested under service,fatigue and ultimate loads. Based on the test observations and results, the experience gained fromthe sequence of construction events including fabrication, casting of UHPC infill transverse andlongitudinal joints, the prefabricated UHPC waffle deck system concept was found to be a viableoption to achieve the goals of AASHTO strategic plan.