Air Entrained Concrete

Canadian Hydro Developers constructed an independent power project in 2004/2005 for generation of electricity in the Squamish, British Columbia area. The facility is a run-of-river hydro plant that diverts water from the Mamquam River through a penstock into turbines located in a powerhouse downstream. The water turns the turbines generating 25 MW of power and is returned to the river directly below the powerhouse. HARD-CEM concrete, because of its abrasion resistant characteristics was specified for the bottom 4 meters of the sluiceway structure which will be subjected to the greatest erosion forces.

The sluiceway structure is an open channel inside a dam designed to collect and divert ice and trash (e.g., logs) in the river before they get into the turbine units and cause damage. For a period of 6 months, during construction of the weir, the entire Mamquam River was diverted through the sluiceway structure with river flows that exceeded 40m3/second. Fully operational, the sluiceway structure will be used to allow sediment to flow through the intake channel during flood events. This diversion will prevent silt from building up in the channel floor. HARD-CEM was utilized to combat the erosion forces due to the volume of water carrying light bedload. Everyone involved in the placement and finishing were impressed with the HARD-CEM concrete’s workability in the challenging construction conditions. HARD-CEM durability and abrasion resistance will result in increased concrete life expectancy and reduced concrete maintenance costs.