Concrete roads cheaper, greener and not as noisy as you think

02 July 2019 | Web Article Number: ME201915016

Construction, Civil & Structural Engineering

CONCRETE pavements offer substantial environmental economic and social benefits and are the sustainable solution to the road networks of all African countries.

That’s according to Bryan Perrie, MD of The Concrete Institute in South Africa, a leading authority on concrete pavements, having authored several books and presented papers at international conferences on the subject.

Perrie said concrete roads – providing they are built by skilled personnel - are the natural choice for projects in developing countries where performance, value, longevity, social responsibility and concern for the environment are paramount.

Concrete roads cheaper, greener and not as noisy as you think

“In addition to a service life which normally exceeds 30 years, concrete pavements require relatively little maintenance and repair and result in long-term savings in raw materials, transport and energy. The reduction in traffic delays caused by road works also cuts fuel consumption and exhaust gas emissions.”

Perrie listed a number of benefits of concrete roads:

  • Safety: Surface texturing of concrete pavement can improve water run-off so that traffic on wet roads does not cause splash, spray and skidding. The light colour of concrete pavements deflects light from vehicles and street lights, improving night-time visibility while effecting energy and materials savings by requiring fewer street lights per kilometre of road.
  • Heat retention: Concrete roads reflect sunlight which helps to mitigate the ‘heat island’ effect. “Research shows that black surfaces exposed to sunlight can become 21ºC hotter than reflective white surfaces. This heats up the air around roads, contributing to increased temperatures in surrounding buildings, necessitating greater use of air conditioning, energy consumption and electricity demand,” Perrie explains.
  • Labour-intensive construction: In countries where unemployment is a major burden to the economy, the manual aspects of the construction of concrete roads can be carried out by members of the local community after on-site training. Their newly-acquired skills can thereafter be utilised in other sectors of civil engineering.

Addressing the perception that concrete roads are noisy, Perrie said a five-year Canadian study showed that they were only 2-4 decibels louder than asphalt. “A conversation registers 60-70 decibels and a whisper, 20 decibels. So, in view of the many other benefits of concrete roads, this is a minor and really an irrelevant factor,” he said.

The Concrete Institute’s School of Concrete Technology, in collaboration with the SA Road Federation, offers a special training course, Concrete Road Design and Construction. The TCI Information Centre, which can be accessed free of charge, houses extensive literature on the subject.

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