Long-term durability of Carbon CFRP Composites applied to R/C Concrete Bridges

University Of Utah, Salt Lake City UT

Investigators

Abstract

The investigation will focus on the monitoring and analysis of the State Street Bridge in Salt Lake City, Utah, which has been seismically retrofitted with Carbon FRP composites. The severe weather changes, the application of salt in the winter, and the freezing and thawing patterns make this a unique study. Test items, plates, and cylinders will be placed at the bridge site and used for destructive testing at predetermined intervals. Further laboratory testing, will investigate single and dual variables. The objectives of this research are to: (a) evaluate the long-term reduction in strength and modulus of elasticity of the carbon CFRP composite due to changes in temperature, alkalinity, chlorides, UV exposure, and freeze/thaw cycles; (b) evaluate the durability of the bond between the CFRP composite and concrete using mechanical, thermal, and chemical testing; (c) evaluate the long-term effect of the CFRP composite retrofit on the strength and structural characteristics of the reinforced concrete bridge; (d) develop a "durability reduction factor" to be used in the design of a CFRP composite retrofit, based on the information gathered from the long-term monitoring of State Street Bridge. Instead of testing only commercial products in the proposed durability study, a matrix of carbon fibers and resins will be utilized. A total of five composite materials will be investigated: three commercial composite products, to be supplied from three independent manufacturers and two non-commercial products.