Texas has the same problem of sinkholes and potholes as Spain but believes it has the solution: plastic roads
It is barely one kilometer but the promise is enormous: converting the roads into a huge plastic recycling plant. Testing began at the University of Texas at Arlington (United States) promulgated by Sahadat Hossaincivil engineer and director of the Solid Waste Institute for Sustainability at the University of Texas, but they have already taken the leap to the road. Hossain tells the story in The Conversationwhere he explains that the project was born from his obsession with recycling plastic. The engineer points out that he grew up in a low-income neighborhood of Bangladesh and that there he observed that people who lived closer to the landfills suffered more health problems than those who lived a little further away. His childhood experience has focused much of his research, focusing on the impact of materials on the environment and possible solutions for recycling them. Among the most complicated to recycle and, without a doubt, the most used: plastic. Now, under their research, in the United States they have launched a project to use plastics used in the construction of roads. And the results are being successful. Harder and more resistant In Texas they have a problem: it’s hot. Very hot, in fact. When building a road, taking the climate into account is essential. ANDIn warmer places, harder bitumens are needed. because they tolerate heat better. The problem is that asphalt also becomes more fragile and breaks more easily. The problems are even more pronounced if a wave of bad weather with a lot of water hits a fragile pavement, as has happened in Spain. A solution could go through make the asphalt a little more elastic but this has an intrinsic problem. And if the asphalt is more elastic, it also resists heat less well and in the harshest months it can soften and melt, as has happened to the United Kingdom in recent years. But this is, always, if we use traditional methods. What Sahadat Hossain’s team is testing is injecting plastics into the bitumen that binds the mixture of stones and sand that makes up the asphalt. At the moment, they are trying to inject plastics that make up between 8 and 10% of the bitumen mixture that binds the rest of the materials. It may not seem like a lot but, according to Hossain, at a test site near Dallas they used 4.5 tons of plastics that came from single-use plastic bags or bottles that were discarded to build a mile. It is a not insignificant amount if we think that we are talking about building about 1,600 meters of road while giving a new use to a material that produces about 400 million tons a year and of which barely 10% is recycled. To be useful, the process requires shred plastic until you get a very fine material that can melt with the bitumen and thus not leave elements in the air. And the result is being good. The first tests were done in university parking lot but they have already been scaling the project to roads with intense road traffic. According to their experience, the asphalt continues to resist heat (with good performance on days that exceeded 100º Fahrenheit, almost 38ºC) and is more flexible than with the traditional system, which reduces the risk of cracks and fractures. Point at The Conversationthat one of these tests has also been carried out in Bangladesh, where a heat wave caused more cracks and fractures in traditional roads while this road with plastics suffered much less wear. It is, therefore, good news when it comes to extend the useful life of the pavement and save money on maintenance. The good news is that the project is monitoring all the results with high traffic volume roads (also the adverse ones such as the possible emission of microplastics when vehicles pass by). And this test is by no means the first. In Rotterdam there was already talk of building these roads with recycled plastics a decade ago. However, its fatigue is much lower. The advantage here is that its performance can be studied under constant and high-tonnage traffic. Photo | The University of Texas at Arlington In Xataka | Until 2020, Spain had the most praised roads in Europe. Now it has something else: a hole of 13,000 million euros