Asfalto efficiente: tecnologia italiana

Efficient asphalt: Italian technology on the road

Old asphalt needs continuous maintenance and is not efficient. But our country is at the cutting edge of experiments with new materials.

by Eni Staff
10 February 2020
6 min read
by Eni Staff
10 February 2020
6 min read

Draining and pollution absorbing asphalt, an Italian invention

Unfortunately, men working on the road with steaming asphalt and black bitumen brushes to fill the holes in the surface is still a common sight today. The holes appear every time it rains in half of Italian cities and on as many secondary regional and provincial roads. When sudden and very heavy rain hits anywhere that maintenance has not been carried out adequately or work has not been done to high standards problems arise. The result is a somewhat precarious situation, especially in many regions where resources are sparse and the solution is antiquated to say the least: shovels, buckets and brushes (trucks if you're lucky). Patching it up until the next rain comes, which is even heavier than the last. And then it starts again, more holes, more inconvenience and new dangers for traffic.
And to think the Italian asphalt and bitumen industry is among the most technologically advanced and innovative in the whole of Europe. And it is precisely here, in our country - perhaps because of its weather - that we have invented a range of asphalts, from water draining and pollution absorbing to those that light up at night and muffle vehicle noise. And more, coloured asphalt and even one that is almost indestructible.

An (almost) everlasting asphalt

The latest news in the area - and absolutely made in Italy - is the almost everlasting asphalt.
The "almost" is a must, especially when it comes to the passage of time. Nothing lasts forever - and nothing is indestructible - but technicians at Iterchimica (a company in the province of Bergamo which has worked in this sector for decades) appear to have come very close, developing a new asphalt with really unique characteristics. It is all down the addition of small amounts of graphene, a carbon based material which comes in very thin films of mono or pluriatomic layers. Here, very small graphene granules are added in small quantities to the asphalt mixture, increasing its resistance to wear to twice that of traditional asphalt. With this new technology, it is also possible to almost completely reuse old deteriorated asphalt, which is milled to renew the surface layer, thus reducing costs and saving a huge amount of raw materials and energy.

An old friend

Another asphalt example but with the opposite characteristics. This is not a new invention, having already been used for decades. Draining asphalt was the first major revolution in the area of road coverings. It is very Italian and widespread over most of the motorway network and also to a large extent on the other main arteries. This is a layer of asphalt which is much more porous than usual, created with modified bitumen with polymers, which allows rain to drain down through the surface to the lower layers where a collection system expels the water off the road. This means you can drive along on an almost dry surface and - at least until rain intensity exceeds certain limits - vehicles will not create water spray.

A cold transportable bitumen

Another important innovation is cold transportable bitumen. This technology was developed by Paolo Italia, an Eni researcher, who was awarded the Eni Award in 2015 (Eni Innovation recognition section) for the technology and over the years has earned a reputation as a real Nobel of Energy.
Thanks to intensive experimental work in the laboratory, which led to the filing of two patents, experimental industrial production of modified sheet bitumen, which can be cold shipped even over long distances, began.
“Being able to handle modified sheet bitumen at room temperature" explains Paolo Italia "solves transport problems, allowing it to be moved further than the current distance limits for hot tankers, and preventing the resulting degradation and performance loss. This innovative product provides for high energy savings during transport and storage, which can be done at room temperature, while for traditional modified bitumen temperatures coming close to 180°C are required. In addition, because it has a high content of modifying agents, after it is mixed with standard bitumen when it arrives on-site, it creates a modified bitumen with the exact same qualities as traditional hot products, which can therefore be used for draining, sound-absorbing and long-lasting road coverings."
Paolo Italia concludes "Finally its particular formulation allows the asphalt to be prepared and laid at a lower temperature than standard, with further energy savings".

The Eni Award 2015 ceremony was held at the Quirinal Palace in Rome

Other excellent asphalts

Another example of a technological asphalt, also offering environmental protection, is that of pollution-absorbing coatings, asphalt with integrated titanium oxides that bind to some pollutants, such as nitrogen oxides and sulphur oxides.
And, still in relation to environmental issues, we note two particularly relevant examples.
The first is sound-absorbing asphalt on which tyres generate less noise, made with bitumens modified with polymers as in draining asphalt.
The second, using fine rubber powders from disposed tyre residue added to the bitumen, makes it possible to mix an asphalt that improves vehicle adhesion, reducing the risk of skidding, especially in rain and contributing, in part, also to the reduction of noise due from car tyres.
In the area of road safety anti-freeze asphalt and luminous asphalt have also been researched. The first contains special mineral salts that lower the freezing temperature of the water that infiltrates the surface of the road covering. While the latter - developed at the Politecnico di Milano - contains tiny fragments of vitreous material that reflect the light of vehicle headlights at night, making driving safer.
And finally, because Italy is the country of colour and fashion, there are also coloured asphalts.
With the use of synthetic binders and pigments, coverings can be created in bright colours or, more commonly, in sienna or blue tones, which blend in with the landscape much better then pitch black.