COBRAE Composite Bridge Conference Report - 'FRP Composites in Bridge Design and Civil Engineering'- Part 2 of 3

摘要

Keynote Presentation - Swiss Federal Institute of Technology: The keynote, by Prof. Thomas Keller, of the Swiss Federal Institute of Technology, dealt with the interaction between composite bridge decks and the underlying steel girder structure, as established by re-decking a test bridge in Switzerland. Lessons learned included the fact that the bonded-on deck appreciably stiffens the basic bridge structure, showing similar "composite action" as would a reinforced concrete deck panel on steel beams. Tests were performed for 10 million load cycles, representing the equivalent of 70 years of traffic loading. The primary failure mode was a ductile failure in the steel, followed by secondary debonding of the composite deck. A significant safety factor of 5 was used in designing for the strength of the FRP composite deck, and the bridge's overall stiffness rose by a surprising 30 percent as a result. However there still are three problems with the approach used: transverse properties, adhesive peeling, and the thick adhesive layer itself.