Concrete Roads

Concrete roads offer durable road construction, help lower vehicle emissions, and reflect more solar radiation than alternatives, such as asphalt. They could also enable in-transport charging of electric vehicles.

Roads are a key enabler of development in both cities and rural areas. Their construction poses the challenge of delivering best performance (in terms of enabling safety, traffic intensity and durability, as well as possible additional duties, such as drainage) as efficiently as possible in terms of resource consumption, cost of construction, and vehicle interaction.

Concrete roads offer solutions to these challenges. Typical construction methods include roller compacted concrete, jointed plain concrete pavement, or continuously reinforced concrete pavement. The visible surface (wearing course) is usually concrete, but a thin asphalt wearing surface can also be added. When an asphalt surface is applied, it is usually to address concerns about vehicle noise, even though concrete roads can be specified and constructed to meet acoustic criteria.

Hybrid solutions are also available with a concrete sublayer and asphalt top layer acting together to form the road structure. Cementitious solutions for soil stabilisation beneath the road structure are also used. The use of concrete for soil stabilisation at initial build reduces energy and material consumption, as it avoids the need to remove poor soil and replace with alternative materials.According to MIT and others’ research on pavement vehicle interaction, stiffer and smoother roads reduce vehicle emissions. Concrete roads are stiffer and, because of their durability, need less maintenance (a benefit in itself) and are therefore more likely to be smoother. As a result, concrete road structures and surfaces help minimise vehicle emissions. This is significant because vehicle emissions can be 100 times more than construction and maintenance related emissions.

A further benefit is that concrete roads have a higher albedo, meaning they reflect a higher proportion of solar radiation than darker materials, such as asphalt, mitigating the consequences of warming from CO2 emissions, reducing the urban heat island effect and reducing demand for street lighting.

One final area of potential benefit in the future is the potential to charge electric vehicles while driving, due to the ability of certain concrete mixes to conduct electricity.

Further reading and sources:

Header photo by Paul Moan on Unsplash