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Earth

Could Plastic Roads Make for a Smoother Ride? (bbc.com) 97

From lower carbon emissions to fewer potholes, there are a number of benefits to building a layer of plastic into roads. From a report: On a road into New Delhi, countless cars a day speed over tonnes of plastic bags, bottle tops and discarded polystyrene cups. In a single kilometre, a driver covers one tonne of plastic waste. But far from being an unpleasant journey through a sea of litter, this road is smooth and well-maintained -- in fact the plastic that each driver passes over isn't visible to the naked eye. It is simply a part of the road. This road, stretching from New Delhi to nearby Meerut, was laid using a system developed by Rajagopalan Vasudevan, a professor of chemistry at the Thiagarajar College of Engineering in India, which replaces 10% of a road's bitumen with repurposed plastic waste.

India has been leading the world in experimenting with plastic-tar roads since the early 2000s. But a growing number of countries are beginning to follow suit. From Ghana to the Netherlands, building plastic into roads and pathways is helping to save carbon emissions, keep plastic from the oceans and landfill, and improve the life-expectancy of the average road. By 2040, there is set to be 1.3 billion tonnes of plastic in the environment globally. India alone already generates more than 3.3 million tonnes of plastic a year -- which was one of the motivators behind Vasudevan's system for incorporating waste into roads. It has the benefit of being a very simple process, requiring little high-tech machinery. First, the shredded plastic waste is scattered onto an aggregate of crushed stones and sand before being heated to about 170C -- hot enough to melt the waste. The melted plastics then coat the aggregate in a thin layer. Then heated bitumen is added on top, which helps to solidify the aggregate, and the mixture is complete. Many different types of plastics can be added to the mix: carrier bags, disposable cups, hard-to-recycle multi-layer films and polyethylene and polypropylene foams have all found their way into India's roads, and they don't have to be sorted or cleaned before shredding.

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Could Plastic Roads Make for a Smoother Ride?

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  • by mobby_6kl ( 668092 ) on Monday March 08, 2021 @11:19AM (#61136602)

    Certainly makes a lot more sense than the solar ones. But besides monitoring the longevity and grip characteristics, I'd also want ot make sure we'd not be grinding microplastics into the air, otherwise we'd just replace a few bottles sitting around with tons of tiny particles.

    • by Type44Q ( 1233630 ) on Monday March 08, 2021 @11:47AM (#61136746)

      If we make the roads out of rubber, we can make the wheels out of concrete or even rocks, like in the Flintstones ("rotational mass" and "unsprung weight" are racist constructs). ;)

    • by Viol8 ( 599362 ) on Monday March 08, 2021 @11:57AM (#61136786) Homepage

      All the additives in the plastics will slowly leach out into the enviroment with the process probably speeded up due to heating up within black bitumen in somewhere as hot as india plus vehicle tyres crushing it. Sure, it may happen in landfill anyway but this guarantees it will.

    • That is currently what we get from tires. If you've ever lived next to a busy road, it's kind of disgusting.

    • by hackertourist ( 2202674 ) on Monday March 08, 2021 @01:58PM (#61137360)

      from TFA:

      First, the shredded plastic waste is scattered onto an aggregate of crushed stones and sand before being heated to about 170C -- hot enough to melt the waste. The melted plastics then coat the aggregate in a thin layer. Then heated bitumen is added on top, which helps to solidify the aggregate, and the mixture is complete.

      The plastic ends up in a fused layer underneath the bitumen. Microplastic abrasion seems less likely than stuff leaching into the soil.

      • Sounds similar to how used tires are already added to asphalt in many places.

      • by Reziac ( 43301 ) *

        I don't see how that's any worse than the layer of bitumen, which is basically petroleum waste. You've already got a nice wide ribbon of toxic waste that somewhat leaches into the ground over time; plastic is probably less reactive and not significantly more toxic even once broken down.

        IOW, by the time it's an asphalt road, worrying over plastic content is kind of silly. And we already melt plastic into structural chunks for use in curbs and the like.

        I know old tires have been ground up and used in the surf

    • My thoughts exactly. As long as there is friction, wear and tear, there will be fine particles dispersed in the air and water. There is no way around it. But now that we have this realization around micro plastics, there is an opportunity to try and think about better ways to construct roads, tires, brake pads, etc so that the impact to the environment (aka the place we human beings inhabit, live, drink, and breathe from) is lessened.

      There's still a lot of 19th century thinking and technology that pervad

    • If this is displacing bitumen, then it amounts to reusing petrochemicals instead of pumping up more from the ground.
    • Comment removed based on user account deletion
    • u-huh, i read the title twice too ...
  • by crow ( 16139 ) on Monday March 08, 2021 @11:20AM (#61136612) Homepage Journal

    We've been hearing about the importance of having less plastic in the environment. Plastic is getting everywhere and into everything. Wouldn't this process just make that problem worse over time?

    What this really highlights is that plastic recycling is essentially a lie. We have all this post-consumer plastic, and nothing useful to do with it. The only real way to get rid of it is to incinerate it to break it down entirely (and generate power), but that also releases other chemicals, so there's no obvious best option.

    • by BAReFO0t ( 6240524 ) on Monday March 08, 2021 @11:32AM (#61136678)

      That is correct. I still remember this going through the news, a few months ago: That the dirty secret is, that plastics aren't actually recycled.

      They always said "Recyclable" and not "Recycled" for that very reason.

      It doesn't make economical sense.
      Not only do do plastics become brittle and re-using the actual PET bottle doesn't work more than sevrn times. But those single-used ones that you are supposed to melt cost more to recycle than to make new ones from scratch. And they are inferior too. E.g. they need to have thicker walls to.compensate for the polymer chains being shorter, or they might burst.

      The only reason plastic bottles have become a thing is because they are lighter and hence cheaper to transport anyway. In all other aspects, they are utter crap.

      • The only reason plastic bottles have become a thing is because they are lighter and hence cheaper to transport anyway. In all other aspects, they are utter crap.

        With plastic bottles, you don't get broken glass in every parking lot.

        • Harder to get sympathy when hit over the head with a plastic bottle too....just sayin Bring back glass bottles!
        • With glass bottles you don't either.

          With asshole citizens, no fines, no deposit system, and most of all, bad cleaning, you do.

          For your curiosity, I recommend watching a few videos of Americans that came to Germany. The ones where you can see the pavement and where they talk about how clean everything is here.
          Glass bottles are very popular here. So populae thar Coca-Cola started selling glass bottles in all sizes again.
          Yet unless it's a party area on the morning after, you could walk barefoot here for years

      • Economic sense I think should not always be the goal. Especially short term economics. Because in the long term the hesitation to spend any money on the problem combined with reluctance to discontinue use of plastics can lead to a long term economic disaster decades or centuries down the road (out of sight, out of mind). I think a lot of the concern about whether recycling, or other ecological programs, is economically viable can be a short sighted goal. This is often combined with a hidden or side goal

      • Glass is also wasteful to return and energy-intensive to produce and recycle.

        • Energy is not the concern. Unless you think we'll use up the sun before we manage to move to a different one.

          And yes, bringing them back is a cost factor. But so is making new plastic, polliting the environment, cleaning the environment, etc.
          Around here we've got delivery services. They roll the cases of glass bottles right into your kitchen if you want, and take back the old bottles while they are there, at no extra cost.. Making the costs so minimal that the prices they offer over what the bottles cost at

    • Re: (Score:3, Informative)

      by thegarbz ( 1787294 )

      What this really highlights is that plastic recycling is essentially a lie.

      No. It highlights that you didn't know what recycling means. Hint: It does not mean that a plastic bottle turns into another plastic bottle. Recycled plastics have always been used for different purposes (including a long history of being used in roads, which have had plastic in various forms in them for the best part of 60 years now).

      • What this really highlights is that plastic recycling is essentially a lie.

        No. It highlights that you didn't know what recycling means. Hint: It does not mean that a plastic bottle turns into another plastic bottle.

        True recycling requires it to be same quality as the original otherwise it is downcycling and you eventually still reach the end of life. Roads might be an acceptable final end of life though as they are relatively permanent and even if they need to be disposed of you have trapped the carbon where it doesn't hurt the environment.

        • True recycling requires it to be same quality as the original otherwise it is downcycling

          Oh, then it's pretty much hopeless. Even recycled paper is usually factored in with new paper because it is lower grade with each recycle.

          Well, glass and metals are really really recyclable.

          • True recycling requires it to be same quality as the original otherwise it is downcycling

            Oh, then it's pretty much hopeless. Even recycled paper is usually factored in with new paper because it is lower grade with each recycle.

            Well, glass and metals are really really recyclable.

            Paper would qualify if you can continue to make the exact same product. If you recycle 50% recycled paper to create 50% recycled paper then you are still managing to maintain the same product. It does mean though that the other 50% is either not being recycled or you are creating more and more each year. The key is to not kick the can down the road or if you do then have a plan for it in the end. Even nuclear power has this problem. You need to have a plan for the external costs and end of life of a pr

      • Sure. Let's have the plastics industry redefine "recycling" so they can pretend that they are doing it.

        Because grinding up plastic stuff then melting it into a road surface is NOT recycling. By that definition, turning trees into paper is recycling.

        • Sure. Let's have the plastics industry redefine "recycling" so they can pretend that they are doing it.

          Sorry kiddo, the plastic industry isn't redefining anything. At no point in no industry anywhere in the world does "recycle" mean that a product needs to be turned back into itself. You may be confusing recycling and reusing, but it's a physical impossibility for us to recycle any material back into its original form except for maybe aluminium, but even then we can't recycle aluminium into its original grade either.

          • Paper is recycled/downcycled into new paper many many times. It's not 100% lossless, but it's not an acyclic directed graph either. And Aluminum is not the only metal that is recycled.

            Recycling implies a cycle where the end product goes back to the start of the process to be cycled through more than once.

            Plastics lifecycle is a straight line one time deal, from oil to plastic to a form that can't possibly be reused by any known process and doesn't break down safely. That's not "recycling" in the traditio

            • by Rhipf ( 525263 )

              So all those reusable grocery bags that say they are made from plastic bottles are a lie?
              If those reusable bags aren't considered recycling then most recycling isn't recycling. A lot of the aluminum will end up in other items than more cans. In fact the can that you sent to be recycled was probably partially a recycled aluminum auto part or recycled aluminum foil or recycled aluminum home appliance, etc.

              • Of course that's recycling, but we were basically sold on a system that takes our waste plastic in on one end, and *mostly* recycles the plastic into other stuff. Maybe not new bottles or bags every single time, but we were taught that if we just sorted and cleaned the plastics well enough, the stuff we put in wouldn't have to be created again, more or less.

                The oil industry KNEW that recycling as we were taught it didn't work, they just promoted it because it meant we wouldn't be as concerned about buying m

      • Also recycling should also have a goal that the original products should be used less in the first place, especially if they're based upon non-renewable resources or which are ecologically harmful. But the message of recycling too often seems to be that it's ok to use lots and lots of plastics because there's a neighborhood recycling collector to get all that ugly trash out of your sight. The consumer may be mistakenly thinking that other people are taking care of things.

        The real ecological solution would

        • Recycling doesn't have a message. It's part of a message. The least important part. You may recall the two other R's in the common catchphrase. "Reduce, Reuse, Recycle". At no point were people saying "Hey we recycle to just go nuts". The message has always been that there were other things to do before and then we recycle as a last resort.

          I shudder to think what you were reading that you got a different message.

    • This was invented and patented back in the 90s in the USA. It never happened because of the push for recycling AND a huge reduction in disposable plastic... which stopped short obviously because it continued until plastic waste was so bad we noticed it. Partial solutions only delay... Microplastics weren't even on the inventor's radar back then.

      The roads will definitely longer which will save in some ways. But most the dust given off will still be RUBBER from the car tires.

      BTW, proper burning of plastic DO

      • We need to keep moving away from burning things to generate power, though.
        • We NEED to do many things but instead choose to ignore the unpleasant problems allowing others to continue and then we support them; indirectly adding to the problems. Complexity and distraction overwhelmed us before the internet did.

          That is the sad reality; can't even point out simple stuff anymore. Proper burning is better than burring trash in even harder and expensive to process forms. If we decide road plastic is a problem later on..."down the road" it'll be a "concrete" problem or "set in stone"...

    • Seriously, not trolling. Even if you recycle it N times it'll still end up in the enviroment eventually. If you burn it instead of using oil, coal or gas you can recover some of the energy used in its manufacture plus its no longer an enviromental issue other than CO2 produced in its combustion (any other gases such as chlorine can be scrubbed) and hopefully the CO2 it does produce would simply replace that would have been created by burning raw fossil fuels.

    • by Aighearach ( 97333 ) on Monday March 08, 2021 @12:05PM (#61136822)

      Post-consumer plastic makes good 3d printer filament.

    • by hey! ( 33014 )

      It's mostly a lie. Less than 9% of plastics are recycled. I've been consciously trying to reduce my plastic use because the sheer volume of plastic waste generated by a single supermarket trip was starting to freak me out.

      Plastic is generally *physically* recyclable, but only #1 and #2 can be recycled profitably and so everything else ends up in a landfill. #1 and #2 are not recyclable if opaque pigments are added to them. I don't see any quick and perfect solution to this, but I think making virgin pl

      • The plastics manufacturers make more money for 'virgin' plastic than recycled plastic so it's in their interests to make recycling as difficult as possible. If there were rules that all plastic packaging possible had to be clear, non-tinted, visibly marked, #1 & #2 only, the problem would be reduced but so would their profits.

        See this 2019 article from the Intercept: https://theintercept.com/2019/07/20/plastics-industry-plastic-recycling/ [theintercept.com]

    • I mean, plastic in giant sheets is a lot better for the environment than lose plastic everywhere. Animals wouldn't eat it, etc.

      What this really highlights is that plastic recycling is essentially a lie.

      Plastic isn't homogenous. This is being touted as a solution for films and certain varieties of plastics (AKA, the various recycling numbers) that are hard to deal with . Tons (literally) of plastic is actually recycled easily.

    • I agree with everything you're saying, but the facts of the matter are:
      1. Plastics aren't going away. Not anytime soon, maybe not ever. It's another genie we can't put back into the bottle (pun unintended). Plastics are too useful.
      2. Roads aren't going away anytime soon either. They'll be with us until our civilzation completely collapses, because ground transportation isn't going away either.
      Therefore if the stuff is just going to pile up, we may as well (re)use it in some way.
      'Recycling', in the conve
  • by SuperKendall ( 25149 ) on Monday March 08, 2021 @11:27AM (#61136652)

    Line the entire roadbed with those plastic rings that hold six packs together. Have you ever tried to tear those by hand? Good luck road cracks trying to break apart that base!

    • Actually, not a bad idea, used as a lattice.
      Another idea:
      Nothing to do with plastic, but I know a 2 block long street section in a town nearby, entirely brick with sand set. Nothing over it, just riprap base underneath. They re-sand and repack once in a while. No potholes. Swells and dips, yes. but no potholes. Only section of miles upon miles of street they don't have to do lengthy repairs to as long as it's maintained.
  • Microplastic and toxic leaching explosion? Definitely.
  • Just like nuclear waste sitting around waiting to cool off, India is at least doing something to keep some of the man-made crap from being loose in the environment. The obvious final goal is to quit making it, but in the meantime, considering that roads are already made of petroleum (tar), this makes sense.
    • by doom ( 14564 )

      Just like nuclear waste sitting around waiting to cool off,

      Nuclear waste is by no means comparable in volume to plastic waste in any industrial society, so you're remark is off-topic trolling intended to sucker people like me.

      • If one chooses not to make the connection between two man-made problems that have demonstrable potential to damage the planet having to be managed by those same humans, then you are free to do so. Given that last month the US DOE green-lighted an Oklahoma company testing fuel made from spent nuclear fuel (https://www.wired.com/story/recycled-nuclear-waste-will-power-a-new-reactor/), I think that there is something in common. These two substances, that were causing few problems before people got involved,
        • by cusco ( 717999 )

          the US DOE green-lighted an Oklahoma company testing fuel made from spent nuclear fuel

          What? They finally allowed it? About frelling time, they've been blocking every attempt for the last 30 years.

  • Road tar just needs to be heated up and plastered back in place to be recycled.
    If plastic doesn't complicate the process I am for it, but I feeling this might not be the case.

    The only solution I see to our oil addition (which plastic is a very large part of) is to become less materialistic and stop buying junk that will thrown away in a year or two.
    • by jbengt ( 874751 )

      Road tar just needs to be heated up and plastered back in place to be recycled.

      Not completely. The lighter constituents of asphalt evaporate, that's why it shrinks and cracks. You need to replace them when resurfacing.

  • by thegarbz ( 1787294 ) on Monday March 08, 2021 @11:35AM (#61136696)

    Plastic gets mixed into bitumen while it's blown to develop a specific set of carefully tuned properties. The amount and type of plastic mixed in not only determines the smoothness but also how well it wears, how well it weathers, and how it reacts with rubber in various conditions.

    The roads used in different countries (or even different areas of the same country) all have various plastics in them to define the required properties. In many cases that even comes from recycled sources.

    • by cusco ( 717999 )

      Prior to the popularization of steel belted radials tires used to be frequently melted into the bitumen. I don't think they can do that any more.

  • by algaeman ( 600564 ) on Monday March 08, 2021 @11:50AM (#61136764)
    How does this affect asphalt recycling? Asphalt is highly reusable, and in most economies a large part of what is laid on roads is already recycled material.
  • So is anyone knowledgeable enough here on the subject of micro plastics and how they are winding up in "everything" these days? And what the biggest contributor is to this? I keep reading almost every month they have now found a new item that is even harder to believe than before that has micro plastics in it. I have read in a few posts here that plastics are already a component in many places in the material they put down for roads. It would seem to me if you have roads everywhere that contain plastics
  • by v1 ( 525388 ) on Monday March 08, 2021 @11:59AM (#61136798) Homepage Journal

    Snow plows would obliterate plastic roads.

    And I can't help but wonder how these roads work out in anything but perfect weather. I know how treacherous new asphalt becomes when it rains, because of how the watr beads up on it instead of absorbing, which sounds exactly like what plastic will do.

    • by jbengt ( 874751 )

      Snow plows would obliterate plastic roads.

      The same way they would obliterate asphalt roads.

      • Re:not in Iowa! (Score:4, Informative)

        by v1 ( 525388 ) on Monday March 08, 2021 @12:32PM (#61136954) Homepage Journal

        The same way they would obliterate asphalt roads.

        And that they do!

        In the northern states, it's concrete FTW

        Asphalt's great for about 3 years, and then it starts to get potholes. And a fill only lasts a few months. Come springtime, they open up like the gates of hell and swallow fill like pouring sand down a gopher hole, while trying to rip your tires off the rims.

    • by diaz ( 816483 )

      I guess you didn't RTFA

      First they put down a layer of crushed aggregate. This is already done in Iowa and everywhere else.
      Then they put down the plastic and melt it into a thin layer.
      Then they put down a layer of asphalt. This is already done in Iowa and everywhere else.

      The plows will never get to the plastic. The only difference between this and a traditional asphalt road is the layer of plastic, which is supposed to add flexibility and stability to the road. More stability means the road will last longer.

  • what about the autobahn level of roads?
    also some roads need to be able handle 70-80+ MPH and lots of trucks

  • Eventually the roads will erode, releasing the plastics as microplastics. Just kicking the can down the road (so to speak).

    Alternatives for plastics don't look good, but a few look better.
    1. Used plastic -> recycle to new plastic. Result: $$$ for inferior plastic. Uneconomical so showstopper.
    2. Used plastic -> burn as fuel. Result: $ with some nasty air pollutants. Somewhat economical from energy production, but awful health costs, so long term uneconomical.
    3. Used plastic -> bury in landfill.

  • Headlines these days. I guess it is now lies, damned lies and then headlines...

  • This idea claims to divert plastic from landfill but isn't laying it on the ground in a road simply a distributed landfill?

    All the problems of plastic microparticles, breakdown and leaching by water, etc - only delayed a couple of decades until the road surface falls apart.?

    • by ebvwfbw ( 864834 )

      I also had this concern. Sounds like the plastic is bound to the bitumen. It'll be there until energy comes along and releases it, such as heating it up. Even then it doesn't sound like much would get into the water.

      What we really need to do is stop using frickin plastics for everything. Especially the plastic water bottle.

  • Perhaps phasing out consumer plastics all together would be better. Simply banning plastics for consumer packaging would be a great start.
  • Plastic ablates into micro particles that end up in the food chain. Its time to stop using plastics in everything except for the most demanding purposes.
  • How does this stop potholes?
  • ... from India? You mean the India where I was born and grew up ...

    Give me a second, I need to wake up from this fantasy...

    Its still there. So not a dream.

    They use movable metal barrier to block the outer two lanes of a three lane high way, 25 feet farther they block the inner two lanes. All the cars, trucks, buses and rickshaws snake through this obstacle course, traffic backs for kilometers...

    all for what? "Check Post". The term of police check point. The police officer randomly peels off vehicles f

  • Asphalt roads are basically infinitely recyclable with an estimated 1% of the removed mass ending up in landfills. That crushes basically everything else for actual recycling efficiency especially since recycled roads are of identical quality. Glass and metal recycling is efficient too, but has lost efficiency due to contamination by dissimilar materials resulting in less desirable alloys. Plastic recycling suffers every penalty possible with the double problem of contamination and every remelt causing brea

  • After all, both asphalt and plastics are petroleum products, one being more refined than the other.

    However I have some concerns with the longevity of the uncovered plastic roads. Basically UV lights (the Sun) breaks down plastic. If you have left toys in the backyard, you notice they crumble to touch after a while. I am not sure how they will prevent the long term dissolving of these plastics roads into sun baked dust in a few years.

  • Plastic? The Great Satan? Certainly not.

    Everything should be on steel rails, known to be the ideal road surface since the 1800s, and cars need to be outlawed altogether. Think of the turtles!

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