| Although several durability tests have been published, the durability of externally-bondedFRP materials remains at some extend speculative. Among the lacking information is thecorrelation between results from accelerated tests and the behaviour of FRP in real serviceconditions over the years. To gather data to fill this gap, three exposure sites were installedin 1997 as a result of an international collaboration between the Université de Sherbrookein Canada and the Public Work Research Institute in Japan. These exposure sites, undervarious climatic conditions, are located in Sherbrooke, Canada (continental cold), Tsukuba,Japan (temperate mild) and Okinawa, Japan (tropical humid). The specimens exposed ateach site include unprotected and coated CFRP coupons, bare carbon fibres, epoxy resinsand CFRP-wrapped concrete cylinders. The mechanical properties of these specimensmeasured at 0, 1, 3, 5, 7 and 10 years, and the recorded exposure conditions includingtemperature, relative humidity, rain and sunshine intensity, will provide a reliable databaseof hundreds of results. With this database, researchers are expecting to be able to correlatemore accurately the results from accelerated tests to the durability under service conditions.Reduction of the strength is observed from the mid-project test results, especially forconstitutive material. However, each of the components, fibres and resin, provides someprotection to the other leading to better tensile strength retention of CFRP laminates and agood durability of the composites. The tensile strength of the tested CFRP laminates isstatistically unaffected by the differences in the climatic conditions. |
