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
STRENGTHENING OF BRIDGE BEAMS AND SIMILAR STRUCTURES BY MEANS OF EPOXY-RESIN-BONDED EXTERNAL REINFORCEMENT
This paper describes the technique of increasing beam strength by means of externally applied reinforcing steel plates, bonded by means of epoxy-resin adhesive. Test methods, application data, and some indication of preferred resin formulation are given. Steel plates are bonded to the beams by means of epoxy-resin paste adhesive. During curing of the resin the plates are held in place by clamps and/or bolts. This provides an inexpensive method of restoring or upgrading the strength of damagaed or substrength concrete bridge and similar beams. To date, results have proved entirely satisfactory, but possible dangers of corrosion on the steel-concrete interface are being investigated. Further work is foreseen that will employ new materials and methods of application and enlarge the scope of the process. (Author)
The Impact of EU Unfair Contract Terms Law on U.S. Business-to-Consumer Internet Merchants
When the Court of Appeals for Versailles issued its decision in AOL France v. UFC Que Choisir2 in September 2005, it sent the message to U.S. Internet businesses that even contractual boilerplate localized for European markets may be invalid in European consumer transactions. In that case, a French consumer advocacy group challenged the terms AOL offered its French customers after AOL had made extensive revisions to its standard form contracts to respond to the concerns regarding those terms expressed in an advisory opinion by a French consumer protection agency. In 2004, a trial court invalidated nearly every term in the revised agreement; the appeals court affirmed on all counts. Subsequently, in July 2006 following concerns raised by the Office of Fair Trading (“OFT”), a United Kingdom government agency charged with “making sure markets work well for consumers,”3 Dell Corporation Limited changed its online terms and conditions to make them fairer to consumers.4 European consumer contract law had an impact in both cases. At issue for AOL France and Dell Corporation Limited was the application of France’s and the UK’s consumer contract law which is based on the Unfair Contract Terms Directive of 19945 and calls into question the validity of many of the terms that U.S. courts routinely enforce in transactions involving American consumers and merchants.