A Ten-Year Check-In on the Condition and Performance of a Challenging Repair of a Damaged Penstock Using a CFRP Liner

The discovery of a buckled steel penstock at the Brian J. Gallagher Generating Station in Almonte, Ontario, leads to repair involving removal of the damaged steel liner and installation of a standalone CFRP liner bonded to the concrete encasement. Repair work was completed in the fall of 2013, and annual follow-up inspections were performed in 2014−2016. A recent inspection was also completed in 2023 at the 10-year anniversary. This case study looks back at some of the initial challenges faced during the design and construction of this CFRP liner, discusses how these challenges manifested as distress in the final laminate, and tracks how these issues fared over a decade of in-service usage. This paper reviews the performance of the CFRP liner, in terms of both structural health and abrasion resistance, and monitors the changes in minor defects over the course of a decade of follow-up inspections.