A research performed at the Universidad Politécnica de Madrid has demonstrated that the temperature for manufacturing and placing the asphalt mixtures can be reduced up to 30 degrees by maintaining a good mechanical behavior.
Similarly, by performing a hybrid life cycle assessment, scientists could precisely quantify the environmental impact and benefits of the manufacture of these mixtures considering the complete supply chain with respect to greenhouse emissions and energy. The outcome was an innovative form of asphalt that is more sustainable for the environment.
In the recent past, the increasing concern related to climate change and global warming has emphasized the need to become more efficient in the reduction of greenhouse emissions and the use of energy. This concern has even touched the field of asphalt mixtures which is striving to create innovative materials that are more considerate of the environment.
To achieve this, Ana María Rodríguez Alloza, a female scientist from Universidad Politécnica de Madrid, has designed a kind of asphalt that can be regarded as more eco-friendly. Primarily, this asphalt is made of rubber powder from old tires. This innovative application would solve the problem of waste which, in spite of being recyclable, is an environmental problem as its synthesis surpasses 300,000 tons a year. Moreover, this can save bitumen—a natural resource obtained from crude oil—and the energy consumed for its production.
Second, this innovative, sustainable asphalt contains a range of organic waxes which, when reaching their melting point, have the ability to reduce the binder viscosity of the mixture, thereby reducing the manufacturing temperature in the asphalt plant.
To manufacture an asphalt mixture it is necessary to warm additives and bitumen at a certain temperature at which this mixture is moldable for its later placing. When reducing the production temperature we also reduce the energy consumption, fuel, and the greenhouse emissions.
Ana María Rodríguez Alloza
The combo of adding a recyclable material and reducing the manufacturing temperature of the mixtures consequently provides an eco-friendly material, apart from providing economic as well as social benefits. “This type of mixture with organic waxes would be especially suitable for warm weather countries such as Spain,” stated Alloza.
The initial step in making decisions and for achieving more sustainable actions for the construction of roads is to provide information related to the environmental implications during the manufacture of asphalt mixtures and other materials.
This study was developed within the Research line of Road for sustainable development from ETSI Caminos, Canales y Puertos at UPM.