Monitoring and service life estimation of reinforced concrete bridge decks rehabilitated with externally bonded carbon fiber reinforced polymer (CFRP) composites

This dissertation develops methodologies to evaluate the integrity and effectiveness of external bonding of carbon fiber reinforced polymer (CFRP) composites to a reinforced concrete bridge deck. This document, while focused on bridge structures, develops techniques to have widespread application to other FRP rehabilitated structures. Wet lay-up and pultruded CFRP composites are applied to the deteriorated decks of the Watson Wash Bridge. A global vibration-based nondestructive evaluation procedure measuring changes in modal strain energy is used to determine stiffness changes in the bridge structure 1 month, 12 months, and 20 months after rehabilitation with CFRP composites. CFRP composite material variation and degradation are incorporated into a measure of the reliability index to estimate remaining service life. The reliability index also provides the means to combine the effects of material variation, CFRP composite degradation, and measured stiffness changes from the field to assess the service life of a FRP rehabilitated structure as shown from a series of progressive damage tests in the field. An approach for service life estimation is used to develop a service life based design methodology where the FRP rehabilitation design is determined based upon requirements of service life and an allowable reliability index.