Title: Strength, Durability and Health Monitoring of Composites Overlays on Civil Engineering Structures

1 Strength, durability and health monitoring aspects of composite overlays on civil engineering structures are discussed. The perspective and benefits of the repair, upgrade, retrofit, and rehabilitation of US civil infrastructure using composite overlays is briefly reviewed. Bond strength, durability, and in-service health monitoring are identified as critical issues blocking the wide acceptance of these novel structural systems in the construction engineering community. A theoretical and experimental research program, set up at the University of South Carolina, is briefly presented. Test methods development, modeling efforts, and proposed outcomes are discussed. The wider perspective of developing national standards and engineering guidelines for the design and utilization of composite overlays on civil infrastructures is also addressed. INTRODUCTION According to the US Department of Transportation and the Federal Highway Administration, there are about 576,000 bridges in the national bridge inventory, and 23% of these are structurally deficient and in need of repair. Several States have demonstrated that advanced fiber reinforced polymers (FRP) can be used to improve the load capacity of concrete bridges. FRP repair technology offers a practical way to rehabilitate aging concrete bridges without disrupting traffic flow. Masonry buildings also form an important component of US civil engineering structures with historical value. Repairs, rehabilitation and upgrades of masonry are required to meet new strength and seismic requirements. The use of FRP composite overlay on masonry has many potential benefits. A major obstacle in the widespread use of these new engineering solutions is the lack of standards and practices for assessing the quality of the repairs and the durability of the composite-to-concrete bond. Figure Error! Not a valid link. presents a few examples of