Retrofit of the Louisa-Fort Gay Bridge Using CFRP Laminates

Abstract

This report details the processes pertaining to the repair and strengthening of the Louisa-Fort Gay bridge, Lawrence County, KY, using advanced composite materials. Site inspections revealed flexural cracks in the reinforced concrete girders of the continuous bridge structure. To determine the cause of these cracks, an evaluation was initiated based on vehicle classification and truck weight data. The results confirmed that certain reinforced concrete girders were stressed beyond the limits allowed by the AASHTO Code. A retrofit scheme using carbon fiber reinforced polymer (CFRP) composite was devised and the amount of CFRP laminates needed for flexural strengthening was determined from moment-curvature analysis. Retrofitting work began in September of 2003, and the project was completed in October of 2003. Crack gauges were installed at the affected areas to monitor the effectiveness of the retrofit. The bridge was inspected on a number of occasions and, as of September 28, 2006, no movement in the crack gauges has been observed.