Asphalt and concrete are ever-present in the transport infrastructure of the world. Are these expensive, unsustainable materials going to be replaced?
Due to the importance of the experience, driving, walking, and cycling on paved roads has to be up for consideration.
Paved roads form the veins of modern economies, accelerating it, easy and enough to transport goods and people, without considering the climate or environmental circumstances. The paved roads we have these days compared to the previous ones are a drastic improvement, namely gravel cobblestones or even wood. Now here comes the question, is bitumen going to be another replacement?
Around 25 million out of 64 million kilometers of roadways in the world are paved, reported from the CIA’s World Factbook. Most of these roads are either made of asphalt (sand, gravel, and stone, using bitumen as a binder) or only concrete. These two are hard to wear, can bear significant weight and variation in temperature. Moreover, they are easy to maintain and repair. Nevertheless, they have some limitations.
Asphalt is likely to rut and is prone to damage from harsh weather and temperature conditions. Also, because it is an oil product, it cant be preserved for a very long time. They are relatively pricy too.
According to these challenges, some companies and researchers have posed their offer as the alternative. What are they?
MacRebur: addition of recycled plastic pellets to bitumen
The bitumen asphalt in most cases 95 % sand, gravel, stone, and 5% bitumen even though that is not the same all the time. Bitumen is a semi-malleable binder. Is it possible to replace some or all the used bitumen with plastic?
This is what MacRebur is, launched by a Scottish company in 2016. MacRebur reuses regular domestic plastic waste and grinds this into a pellet, which can then be added to the asphalt mix as a supplementary binder. This process needs no alteration to asphalt manufacturing plants. MacRebur’s product does not change bitumen with plastic but, depending on the surface being built, it decreases the required amount.
Plus reducing the amount of plastic moved to a junkyard, MacRebur also makes this claim that its product is more long-lasting and lower-priced to maintain than asphalt, meaning cost-savings for councils.
Notwithstanding being comparatively young, the company has been using its material successfully in trials around the United Kingdom.
Scientists at Aston University have created new ‘bio-bitumen’ out of bin waste.
Should we stop at only recycled plastic? A team of researchers at Birmingham’s Aston University have just issued observations of a new ‘bio-bitumen’ product made from general domestic garbage.
The scientists tested warming rubbish – such as paper and textiles, plastic, organic materials– at around 500°C in with no oxygen, in the process of pyrolysis. Resulting in A goopy black substance that looks like bitumen in so many ways.
Even this new idea hasn’t been used in definitive experiments on the field yet, Birmingham Council and Highways England have shown an interest in testing the product. As they start, it still requires to be blended with bitumen in like MacRebur’s pellets – yet they highly believe that their product could, in the end, replace bitumen completely.
Acquiring more out of paving
Contemporary roads offer one practical function: provision of a flat surface to drive or walk on. American start-up Solar Roadways does not agree to that: – to turn roads into a source of energy.
The company has devised a type of solar panel that can be walked and driven on, and this offers some relatively unique possibilities. Most notably, the solar panels would be able to create electricity.
Solar Roadways lays claim that if its product all paved surfaces are off and instead their product is implanted in the US, they would be able to generate three times more than what the country is currently in need of, in terms of electricity.
In the first place, the product is most possibly going to be used on driveways, enabling home-owners to generate their needed electricity, or on urban pavements or car parks for street lightings and things like that.
Likewise the selling point of electricity generation, Solar Roadways’ product comes with other advantages too.
The paving is sectional, meaning that if one particular panel break, only one single person is enough to come out in a truck, pull it out and a new one – that is much easier than filling in potholes.
So there are more innovative applications, too. The product has LED lights, which show lanes (instead of paint) and they also have this ability to get programmed for displaying messages on its surface like ‘slow down’ or ‘speed camera ahead.’
moreover, when it snows, there is this option that its surface temperature will be increased to help melt the ice and improve safety.
At this time, the company has won acquired rounds of funding from the Department of Transport in the US and has tested it in certain cities, as
well as utilizing it in private driveways.
Using lignin to create a bio-asphalt cycle path in the Netherlands
Lignin is one of the various types of organic polymer that exists in the plant cell’s walls which gives them their shape and make-up. It is also a by-product in the industry of paper, among others. In 2015, a Research Centre in the Netherlands experimented the use of lignin in co-occurrence with bitumen in a 100m stretch of road which is a crowded and continuously used driveway. Until now, the results have been a success.
The researches will always be going until they find a suitable replacement for the bitumen in the mix, but the center freshly built a cycle path at Wageningen University utilizing three different kinds of lignin, all of which were a resource as by-products in other industries. Finding the most cost-effective source of lignin is the objective of these researches, and since the cost of it is very high, the research team is anticipating a breakthrough in supply within the next few years.
Dutch city experimenting new Plastic Road
although many innovations in road materials seek to copy and replace bitumen, one Dutch project has adopted a different approach by creating thoroughly pre-manufactured road sections from recycled plastic.
The rightly-named Plastic Road uses 100 percent recycled plastic from material that is being burnt – and the team intends to use the collected plastic from the seas. Engineers of the firm have discovered a new method to recycle this plastic into hollow blocks, that can create a double function of a road surface that makes cables possible, and also drainage water, to pass beneath.
The blocks are sectional, and they can be simply laid out and removed, which can incredibly cut the required time for building roads. Moreover, it makes the maintenance way simpler.
The building of a pilot with cycle path of 30m is ready for beginning in September 2018 in the Zwolle city.
Primary steps for the alternatives
Clearly, there is a lot of innovation ongoing while researchers and businesses are trying to find alternatives for asphalt and concrete – which they have both dominated more than 90% of road-paving materials for the last hundred years.
However, until now majority of these options as alternatives are new in their development, that require much work, also years of experience and testing is needed before they can turn into a considerable threat for both asphalt and concrete. Up to that day, these two will remain as the kings of the roads.