The Rideau Canal

[Richard Eade]

I’m not sure where that “ice pathway” is, but it looks as if it is in an area that doesn’t get a lot of frost-heave. The picture shows the refrigerant tubes and re-bar before the concrete is poured. There does not appear to be any segmentation of the tubes to create individual, isolated, ‘cold pads’, in case of a break.

In Ottawa, there is a reason that we no longer use concrete roads. They crack, and the slabs then tip differentially. This is a main cause for Carling annually making the top of Ottawa’s worst road list. Carling still has crooked, moving, concrete slabs under the asphalt.

What you seem to be suggesting is an 8 km long concrete pathway running along the bottom of the canal – adding a floor to the canal. This would need a substantial base, likely involving driven piles and a full substructure. Remember, any material under the concrete pad will be saturated. Show me a concrete sidewalk in Ottawa that hasn’t cracked within the first few years – even though they are constructed in relatively short segments.

You might have noticed that the chilled ice surfaces in Ottawa tend to be inside. This allows the base under the pad to be kept dry and free from frost-heave. An exception is the Rink of Dreams. It is outdoors, but it is built on the roof of a below-grade parking structure – which means that there will be no frost-heave under the pad of the Rink of Dreams.

Basically, what that picture is showing would not be suitable for Ottawa. Here, we can’t even get heating elements embedded in concrete LRT platforms to be reliable.