The number of maintenance and rehabilitation interventions will become gradually more frequent in order to repair, amongst others, cracks appearing on the road surface. Repairing asphalt pavements by traditional methods can indeed extend the life service for the network but at a high cost: first of all, it requires public administrations increasing funding; second, it entails an an environmental impact due to the large amount of natural resources, and finally, it limits the mobility of people and goods.
Approximately 1% of EU GDP is lost due to disturbances in the transport flow, part of which is on account of repair, maintenance, retrofitting and revamping. In addition, natural resources are also highly used to extend the lifetime of any road. A recent study from the OECD highlighted the high number of natural aggregates used during road construction (i.e. 10.000 m3 per Km in a two-lane road). Further research from the asphalt sector has unveiled that approximately 158 tons of fuel are needed per Km of road.
In this context, research in more efficient and sustainable road maintenance techniques will contribute to extending the lifetime of the network, optimise traffic flow and ensure minimum performance in terms of safety and quality.
The development of the induction heating technique has put researchers on the right path to deploy a new and cost-effective solution able to extend the lifetime of asphalt mixes. In this sense, the HEALROAD consortium goes one step beyond by developing, optimising and validating asphalt mixture wearing courses as well as steel-fibbers to facilitate self-healing via induction heating.
When micro-cracks appear in the wearing course (normally between after 3-5 years from its construction), an induction heating generator will pass through the road surface heating up the magnetic particles. Bitumen will then melt and flow through the micro cracks in order to close them. Initial estimations confirm that the lifetime of the road can be extended more than 30% by using self-healing combined with other maintenance actions.
This preventive maintenance will not only be able to postpone the replacement of the asphalt surface during years but also to deploy a low-cost measure able to be implemented at low traffic hours with the consequent minimal impact on mobility. HEALROAD could be specially applied on sections such as bridges, tunnels or congested areas where small disruptions lead to severe impacts on traffic flow.
The consortium aims to develop a technique which ensures the best value for money and resource efficiency from a road asset management perspective, as well as improving traffic management by reducing the number of roads closed for maintenance.
Although significant advancements in self-healing have already been achieved individually by HEALROAD partners, several issues and uncertainties have been identified during the technical and market deployment of the technique. In this sense, the new consortium brings together a team able to overcome current implementation problems combining experience and knowledge from different backgrounds.
The new HEALROAD process will be validated at laboratory scale to verify the reduction of the environmental impact and economic costs by using LCA and LCC techniques. Technical barriers for the future industrialisation and market uptake of healable asphalt mixes via induction heating will be removed by promoting a technology made in Europe and developed by European partners.
HEALROAD is co-funded by the ERA-NET Plus Infravation 2014 Call that aims at cost-effective advanced systems, materials and techniques in road infrastructure construction and maintenance.
In order to deliver the full benefits of research and development activities carried out in the transport infrastructure sectors, Infravation brings together EUR 9 million funding from the Netherlands, Denmark, France, Germany, Iceland, Israel, Italy, Norway, Spain, Sweden, USA and the EU.