POLYMIX
Polymer waste in asphalt mixes: a way to improve the sustainability of roads and infrastructure
Objectives
Creating new environmentally friendly asphalt mixes, using polymer waste to modify them.
Description
AIMPLAS, in collaboration with Acciona Infraestructuras, the General Directorate of Highways of the Community of Madrid, and under the coordination of the University of Cantabria, has successfully developed an innovative asphalt mixture that is more resistant and sustainable than conventional ones, thanks to the incorporation of plastic waste in its production. This asphalt incorporates—each type independently—end-of-life tyres (ELTs), polypropylene caps, polyethylene packaging, and polystyrene hangers, and was used to pave a total of two kilometres of the M-300 in the approaches to Alcalá de Henares.
After studying the performance of the paved road section over the past 18 months, the POLYMIX project partners have concluded that the new asphalt mixtures not only meet the requirements set out in the technical specifications for use in road construction, but also that the mixtures containing polymeric waste exhibit a significant improvement in resistance to plastic deformations compared with conventional asphalt. This results in better performance against rutting, which is particularly important under high temperatures or slow heavy traffic.
In addition, there is a general increase in stiffness without compromising—and in some cases, such as ELTs, even improving—fatigue performance. These mechanical properties make the POLYMIX mixtures a wearing course capable of withstanding higher traffic loads, thereby improving the structural capacity of the pavement.
Rutting test results: The results show that the POLYMIX mixtures significantly increase resistance to plastic deformation compared with the reference mix. In the case of polypropylene (PP), the resistance is almost doubled.
For ELTs and PP, the technical and economic feasibility study concludes that, thanks to these innovative components, the mixtures could be produced with a reduced thickness due to their improved properties, thereby lowering production costs.
Environmental and Economic Advantages
The use of an alternative asphalt like that developed in the POLYMIX project offers multiple benefits for both the environment and the economy. On one hand, it allows for a reduction in the volume of raw materials used in production, such as natural aggregates. On the other hand, it provides new pathways for reusing large volumes of plastic waste through a simple method that can be incorporated into any asphalt plant. In this way, if its use were extended nationwide, waste could be processed close to where it is generated.
Moreover, life cycle analyses confirm that the incorporation of polymeric waste results in more sustainable roads with a lower environmental impact.
The results of the POLYMIX project (LIFE10 ENV/ES/000516), funded by the European Life+ programme, have been measured through a series of monitoring tests carried out by the Public Works Experimentation Centre (CEDEX) of the Spanish Ministry of Transport.
LIFE Citizens’ Award
The POLYMIX project received the LIFE Citizens’ Award for the best 2015 LIFE Environment project. The award was presented during EU Green Week in Brussels, at a ceremony held in the The Egg congress centre, where BREAD4PLA, also coordinated by AIMPLAS, was recognised as well.
The LIFE Citizens’ Award gives recognition to this project, funded by European funds by means of the Life+ Programme, aiming to obtain innovative asphalt mixtures more resistant and sustainable than conventional ones, thanks to the incorporation of plastic wastes in its production. These are four different types of asphalt, wherein used tyres, polypropylene caps, polyethylene packages and polystyrene hangers have been added to its composition respectively. With the new mixtures, a total of 2 km of a stretch of the M-300 in the approaches to Alcalá de Henares were asphalted. After a review of the asphalted stretch’s behaviour, the POLYMIX project partners have reached the conclusion that the new asphalt mixtures not only comply with the requirements to be used in road construction, but also obtain a marked improvement in the resistance to plastic deformations with respect to conventional asphalt mixtures. Thus, through its use, the volume of raw materials used is its production is reduced, as well as the maintenance cost, since they have a longer shelf life.
Popular election
For the second consecutive year, the public has had the opportunity to vote for the best 2015 LIFE Project from a list of 24 projects selected by experts on Environment, according to strict criteria and wherein there was also BREAD4PLA, another project counting with the participation of AIMPLAS. The award given to POLYMIX was collected by Professor Daniel Castro, project coordinator at the University of Cantabria and technical director at GITECO, in a ceremony held on Tuesday in The Egg congress centre in Brussels. In this event, five other awards were given to the «Best of the Best» LIFE Nature projects, one award to the «Best of the Best» LIFE Information & Communication projects and five awards to the «Best of the Best» LIFE Environment projects. As a novelty, they all were anounced in the ceremony.
Funding
