Harvesting the unexplored potential of European waste materials for road construction

•Waste materials in the urban and peri-urban environment is reviewed and quantified.•Waste materials suitable for re-use in roads reviewed.•Many waste materials have similar or superior properties to virgin materials used in roads.•It is estimated that 16% of the available waste quantities in Europe could be recycled in roads.•Use of waste materials in roads can lead to significant cost, CO2 and energy savings.

This paper demonstrates how a considerable amount of waste produced in the urban and peri-urban environment can be recycled in asphalt roads. The example presented is from Europe, however, the barriers and conclusions are universal. It was shown that various waste materials such as glass, asphalt, concrete, wood, plastics etc. have a potential for re-use in asphalt roads. The available quantities of the European target waste materials that would otherwise be incinerated or disposed in landfills were considered. It was shown that there is high potential in Europe for recycling in road construction, in particular, under the hypothetical scenario where 33% of new roads would be made of the target waste materials (excluding RAP which is already recycled), it is estimated that 16% of the available waste quantities could be recycled in roads. Four hypothetical roads were analysed showing a considerable savings in costs, CO2 and energy in comparison to conventional asphalt mixtures using all virgin components.