Evaluating Long-Term Performance of Composite Materials used to Repair Corroded Pipes. . .etc.	Time: 1:30 PM	Room C
Chris Alexander, Stress Engineering Services, Inc. The long-term performance of composite materials is fundamental to their success in being used to repair damaged piping and pipeline systems. In order to evaluate long-term performance, factors that must be considered include time-dependent material degradation and response to sustained and cyclic loading conditions. For the past 15 years Stress Engineering Services, Inc. has been actively involved in evaluating the performance of composite material used to repair damaged pipes. Based on industry feedback regarding the use of composite materials, a significant portion of recent work has been focused on long-term performance. This presentation will provide details on analysis and full-scale testing efforts performed for the pipeline industry and composite manufacturers. Of particular note will be discussions on a 10-year study co-sponsored by the Pipeline Research Council International, Inc. involving buried pipe samples repaired using composite materials installed by 12 manufacturers from around the world. Additionally, technical details will be provided on pressure cycle testing conducted to evaluate the fatigue life of repaired corrosion defects having a depth equal to 75% of the pipes normal wall. This research has included evaluating the use of carbon-epoxy systems that have successfully cycled more than 500,000 times at a pressure differential equal to 50% of the pipe’s maximum allowable operating pressure.