Construction World October 2017

ROADS & BRIDGES

Concrete roads offer superior fuel economy With fuel price constantly rising, the lower fuel consumption offered by concrete pavements should be an important factor for future road transport planning, says Bryan Perrie, MD of The Concrete Institute.

Perrie says because of the social and ecological importance of reducing fossil fuel consumption, several studies and research projects concerning the effect of pavement type on the fuel consumption industrial goods vehicles and cars have already been carried out. The best-known study is that of the National Research Council of Canada. “The Canadian NRC did a series of four investigations, which were progressively extended with additional test phases on various types of pavements and vehicles in different seasons and using a variety of statistical models. Reduced fuel consumption by heavy goods vehicles was seen in all phases for concrete pavements when compared to asphalt pavements. “The final phase, which was also the most complete and evaluated a range of pavements with various degrees of evenness and with observations made in all seasons, revealed the smallest differences but still showed that the ‘fuel saving on concrete pavements compared to asphalt pavements - both for an empty and full tractor-trailer unit - ranged from 0,8 to 3,9% in four out of five periods in the year. This was found in results with a field of reliability of 95%.”

Perrie says an average fuel saving of 2,35% is certainly not negligible and

would represent an immense difference in overall fuel consumption and emissions of greenhouse gases (GHG) over the lifetime of a busy freeway. Laboratory research by the TRL (Transport Research Laboratories) in Great Britain, commissioned by theHighways Agency, was carried out to determine the effect of the rigidity of the pavement on fuel consumption. The reduced deflection of concrete pavement led to a 5,7% reduction in rolling resistance, also resulting in fuel savings. Similar results have been obtained from extensive research done in Sweden, Japan and the US states of Texas and Massachusetts. “Apart from the type of pavement, evenness and surface texture are important factors influencing fuel consumption. The quality of the finished concrete surface plays a crucial role: a good-quality and evenly-laid concrete pavement retains these qualities for decades; a concrete pavement with undulations or uneven patches will require difficult, expensive treatment to obtain the desired ride quality,” Perrie states. 

More concrete highways would mean lower fuel consumption, Bryan Perrie, MD of The Concrete Institute, has stated. Pictured: work in progress on concrete pavement construction in KZN.

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CONSTRUCTION WORLD OCTOBER 2017