The Concrete Alternative for Sustainable Roadways
An often overlooked paving solution is gaining ground in Canada. Widely used in the U.S., concrete offers many advantages for roadways in the Canadian climate. It minimizes potential for potholes, requires little repair or maintenance and eliminates the need for spring thaw weight restrictions. It's often more economical than asphalt in the long haul, and it brings environmental and safety benefits.
Sustainable practices in paving can go hand in hand with good economic sense. This is certainly true of concrete pavements. Quite simply, they last longer than asphalt roadways, and need fewer repairs and less maintenance over their lifetime. The longevity of concrete pavements is well documented. Numerous concrete highways in North America have lasted 30 years or more, supporting traffic volumes much greater than originally anticipated.
View animation on Fuel savings for heavy trucks on concrete pavements in Canada
Particularly because of its long life, concrete is an economical, cost-effective pavement solution that consumes minimal materials, energy, and other resources over its lifetime. But concrete pavement has other "green" features beyond longevity that make it highly desirable:
- Properly constructed concrete pavements reduce pavement deflection, which in turn reduces heavy vehicle fuel consumption and its associated GHG, NOx, SO2 emissions.
- Concrete pavements have a substantially lower energy footprint than equivalent asphalt pavements from a life cycle assessment (LCA) prospective. When considering energy use for raw material production, material delivery, pavement construction, and pavement maintenance over a 50-year period, concrete pavement is clearly more sustainable.
- Reduced congestion due to fewer construction zones over the life of concrete pavement leads to more energy savings and reduction in pollutants emitted by vehicles.
- Concrete pavement mixtures incorporate industrial byproducts (i.e. fly ash, slag cement and silica fume). Using these byproducts lowers waste disposal needs, reduces the demand on virgin materials, and conserves natural resources.
- Concrete pavement itself is reusable and 100% recyclable.
- Concrete pavement requires less subbase aggregate material for structural support than asphalt pavements, thereby minimizing the use of non-renewable resources.
- The lighter color and increased reflectivity of concrete pavements improve nighttime visibility, reduce the amount of power needed to illuminate roads at night, and help mitigate urban heat island effect and smog generation.
- Typically, 92% of the volume of a concrete pavement consists of materials that require very little energy to obtain and have a low CO2 footprint, including sand, gravel, water, air, and industrial byproducts.
- Concrete’s rigid structure minimizes the potential for hydroplaning and formation of potholes.
- Optimized concrete pavement surface textures produce quieter pavements over longer periods of time, reducing noise pollution.
- Concrete pavements designed with pervious concrete shoulders minimize surface-water discharge and help replenish groundwater aquifers.
Now available as a free download, the Athena Impact Estimator for Highways
This new software package provides life cycle assessment (LCA) results for the materials manufacturing, roadway construction, use and rehabilitation life cycle stages. It allows custom roadway design, or users can draw from a library of 50 existing pavements, this software allows for quick and easy comparison of multiple alternative design options.
An overview of the software is available here, and the software can be downloaded here. Please click here to register for an upcoming webinar on the Athena Sustainable Institute Environmental Impact Estimator for Highways .