City of Montreal’s CFRP Pipe Repair Project for 2100mm (84 inch) Mains

Abstract

In August 2024, the City of Montreal faced a significant water main break when a 2100 mm (84-inch) diameter water main failed along René-Lévesque Boulevard, near the Jacques-Cartier Bridge in south-central Montreal. This incident resulted in the loss of approximately 40 million litres of drinking water, severe flooding to multiple properties, emergency responses from the city, and displaced over 140 residents to hotels. The failed pipe was an AWWA C301(E) pre-stressed concrete cylinder pipe (PCCP) installed in 1985. A 2018 inspection of the pipeline identified deterioration in some segments, prompting officials to implement an inspection schedule. Despite condition assessments and prediction modelling indicating that the deteriorated pipe segments were suitable for at least another decade, the pipe ultimately fell short of its expected service life. Following conventional repair of the broken pipe and subsequent inspections, a few other deteriorated pipe segments were found and required intervention. To minimize future disruptions and traffic impacts, and in response to concerns following the 2024 pipe failure, the city opted for a fully structural trenchless repair solution. This approach involved accessing the pipe through existing manways to rehabilitate it from inside before returning it to service. The project team selected internal CFRP (Carbon Fiber Reinforced Polymer) strengthening for four pipe segments deemed deficient and critical. This paper details the project activities required to install the fully structural CFRP repair using a unidirectional advanced composite system, which is NSF certified for potable water systems. The repairs were successfully installed by local contractors trained and certified by the CFRP manufacturer.