Strengthening of Bridge G-270 with Externally Bonded Carbon Fiber Reinforced Polymer (cfrp)

Disclaimer The contents of this report reflect the views of the author(s), who are responsible for the facts and the accuracy of information presented herein. This document is disseminated under the sponsorship of the Center for Infrastructure Engineering Studies (CIES), University of Missouri-Rolla, in the interest of information exchange. CIES assumes no liability for the contents or use thereof. The mission of CIES is to provide leadership in research and education for solving society's problems affecting the nation's infrastructure systems. CIES is the primary conduit for communication among those on the UMR campus interested in infrastructure studies and provides coordination for collaborative efforts. CIES activities include interdisciplinary research and development with projects tailored to address needs of federal agencies, state agencies, and private industry as well as technology transfer and continuing/distance education to the engineering community and industry. Abstract This report presents the results of a pilot study to apply externally bonded Carbon Fiber Reinforced Polymer (CFRP) sheets to strengthen a simple span reinforced concrete solid slab bridge built in 1922. Strengthening with CFRP sheets was accomplished in three days without traffic interruption, and preparation consisted of only light sandblasting. Bridge G-270 is the only load-posted structure on a heavy truck route that serves a lead mining operation and the objective was to strengthen the bridge to allow removal of the load posting. The laboratory testing included the static flexural test of two full-scale beams, designed as a unit strip from the existing bridge deck, and the fatigue bond test of coupon-type specimens. Two reinforced concrete beams, a control beam and a beam strengthened with externally bonded CFRP were tested under four point bending. Coupon-type specimens consisting of unreinforced concrete beams with a reversed T-shaped cross-section and with a CFRP sheet applied to the bottom were tested. The purpose was to investigate the behavior of bond between CFRP sheets and concrete under fatigue loading. The field load testing of the bridge, before and after strengthening, was performed by the University of Missouri-Columbia to verify the performance of the bridge after the application of externally bonded CFRP. Long-term field measurements also were conducted to monitor the durability and the strain condition of the strengthened system. Pennsylvania State University conducted the monitoring of durability by studying the electrochemical effects of the CFRP material on the degradation of the reinforcing steel. Fiber-optic strain sensors were applied to the FRP reinforcement and the concrete …