Readers please note: Ms. Sheri Sutherland of RMCAO responded to this article in a letter posted January 11, 2010. Click here to read her response.
In a session at Construct Canada, Sherry Sutherland, technical engineer at the Ready Mixed Concrete Association of Ontario (RMCAO) , presented a new online tool for estimating whether a concrete or an asphalt road is the most economical alternative.
The CANPav website program allows the designer to select both the cross sections and the construction cost inputs, and then allows him or her to compare the costs of paving municipal streets or commercial parking lots in either asphalt or concrete.
Currently about 3% of roads are paved in concrete, most being large expressways (Highway 407 in Toronto, for example). Now, however, the concrete industry is hoping that concrete paving will be used more in municipal roads, streets and parking lots.
Most engineers think concrete will initially cost about three times as much as asphalt, Sutherland said, but the tool will show that this is not always the case. And while it is well known already that concrete will provide a good payback over its lifecycle, the RCMAO program will show that concrete is often more economical than asphalt even at a first cost basis.
The environmental benefits of concrete include its reduced repair and maintenance costs. Typically asphalt needs replacing in 3 to 12 years, whereas concrete can last 20 to 30 years. Concrete paving also requires less aggregate for the base, saving in materials and trucking.
Another advantage is its reflectance, which can save 30% in lighting costs in car parks.
Even utility cuts and repairs are not problematic, according to Sutherland. They can be patched with precast panels overnight.
The RMCAO is also testing pervious concrete surfaces for parking lots and lay-bys, with four current projects in Ontario and possible eight next year.
The CANPav online tool is free, at www.canpav.com