Chute-à-Caron Dam

Inspection, condition assessment and rehabilitation strategy to extend the service life of the hydro power plant

Chute-à-Caron hydro power plant was built in the late 1920s and commissioned in 1931 on the Saguenay River, just upstream of the town of Jonquière, in Northern Quebec. It consists of a 55-m high, 800-m long dam closing a reservoir that supplies water to two Power Stations.

Chute-à-Caron concrete dam structures and gates were showing signs of aging, therefore, Rio Tinto Alcan contracted the engineering firm SNC-Lavalin to plan and manage a project to rehabilitate the dam structures in order to extend the service life by 30 years.

To ensure compliance to durability design specifications and achieve the desired service life, this project required input from various specialty consultants that was instrumental for the successful completion of this major rehabilitation project.

Acting as an engineering consultant on concrete durability design, SIMCO’s scope of work consisted in performing a comprehensive investigation to identify the causes of the concrete degradation problems and to identify why previous repairs had not been durable. It also included recommendations for the rehabilitation of the damaged structures in order to extend their service life.

SIMCO performed a complete characterization of specimens extracted from different parts of the structures to identify the nature and the extent of the deterioration mechanisms affecting the concrete as well as investigate why previous interventions had failed. Results provided a better understanding of the current condition of the structures and their residual service life.

The analyses performed helped to optimize the volume of concrete to be removed from the different parts of the dam and led SIMCO’s team to assist in the selection of proper rehabilitation techniques. SIMCO also provided the design of repair materials required for this specific project and recommendations in order to avoid similar repair problems previously experienced.