Health monitoring of bonded composite repair in bridge rehabilitation

Structural rehabilitation with carbon fiber reinforced composite materials has proven to be an excellent way to enhance/repair steel reinforced concrete structures and prolong their service lives. However, disbonds between composite repair patches and host structures continue to be a great concern of this technology. In this paper, a built-in piezoelectric sensor network based structural health monitoring system is introduced for monitoring the disbonds between composite repair patches and the host structures. This diagnostic system combines the sensor network, diagnostic hardware and data analysis software allowing for real-time monitoring of the integrity of the bonded repair. The effectiveness of detecting disbonds using the system has been demonstrated on a full scale bridge model in a laboratory setting. The bridge model was loaded incrementally to failure, and disbond monitoring was carried out during the loading intervals. Test results showed that the system could detect the disbonds before they have a noticeable effect on the global stiffness of the bridge model