Durability Assessment of the First Externally Bonded FRP Repair of a Publicly Owned Bridge in the United States after 26 Years of Service

Abstract

Although carbon fiber–reinforced polymer (CFRP) composites have been extensively used to rehabilitate many deficient bridges, data warranting their long-term performance is lacking. Current durability testing of CFRP composites involves accelerated conditioning as a part of material specification requirements to ensure that they maintain mechanical and physical properties during their service life. However, relating accelerated conditioning test data to material performance under real-time aging is not possible without field data. Work conducted at the University of Delaware in the early 1990s resulted in the first full-scale application of externally bonded CFRP on a publicly owned bridge in the United States. The original intent of CFRP strengthening was to extend the service life of the Foulk Road bridge in Wilmington, Delaware by 5–10 years. As one of the earliest CFRP-rehabilitated bridges in the United States, it offers a unique opportunity to study CFRP durability over a time span of 26 years. Field evaluation and laboratory testing (calorimetry, spectroscopy, scanning electron microscopy, and tensile testing) of CFRP samples collected from several girders were employed to investigate CFRP degradation and bond quality. The results indicate that after 26-year-long service life, the condition of CFRP repairs considerably deteriorated.