> flame retardant chemicals used to treat geofoam were shown to be accumulating in the ground, which led to their [i.e., the flame retardants’] discontinuation in Europe but not the US
It appears that people are paying attention to the ecological impact. (In some places, at least.)
Its inert, so its not biodegradable, but it also doesn't break down the way that styrofoam* does. And it can be re-used. I'm not convinced that any of this makes it A Good Thing tbh, but it is possibly less bad than some of the alternatives.
Um, this is expanded polystyrene, just with a fancy "polite" name. Per TFA:
Despite its uncanny appearance, geofoam is incredibly prosaic. Essentially, it’s polystyrene. Expanded polystyrene (EPS) geofoam — the most common type — is made from small polystyrene resin beads that contain microscopic cells filled with a blowing agent, which expand when exposed to steam under controlled pressure and are molded and fused into a brick shape.
The production of concrete is responsible for a ton of pollution in the world and while there's significantly lower environmental impact concrete available, few projects use them because of its higher costs for primarily environmental benefits. The distribution of the lifecycle of the environmental impact matters and if things are pretty bad now I'd strongly consider anything with backloaded environmental costs over ones that have environmental costs incurred up-front.
The bit about petroleum solvents, makes me wonder about sinkholes. "causes it to dissolve and break down into a non-load-bearing sludge", so if some joker tips a bottle of that in the park then a sludgy hole in the ground will start forming?
"Biodegradable essentially means that an item can be broken down into increasingly smaller pieces by bacteria, fungi or microbes to be reabsorbed by the surrounding environment, ideally without causing any pollution."
So it degrades, but causes pollution, therefore it is not biodegradable. That is my understanding.
If the foam blocks are buried, it's less likely they'll make it into the water cycle. (That's not to say they won't cause other problems.)
Also, all the samples collected are not biodegraded, but rather the actual molecule of plastics that's simply gotten smaller and smaller. See "microplastics":
If there ever was an example of "f-ck you, future generations", it would be this.
These blocks will eventually need to be disposed of, or they will become rubble which will "naturally" decay - and by decay I mean gradually have bits eroded off and scattered into the wind/water.
Once they cease to be solid blocks, they become virtually impossible to clean/dispose.
You know how maddening it is when you try to break apart styrofoam packaging supports to fit it in a garbage bag, and all those bits cling to you and refuse to go in the bag? This is that, only writ large over the entire Earth.
Anyone looking over my comment history knows that I am nobody's fool for overblown environmental crises. But just look at that video of them piling up the blocks. Those little clingy granules are going everywhere already, and that's before anybody tries to chop up some infrastructure they've built with this.
I think it's disgusting that polystyrene is legal at all.
It contains toxic chemicals, and in any other context outside of construction it is considered trash-- pollution. And in construction it becomes trash once torn down. It is outlawed in Europe as a single use plastic. And it should be in the US and rest of the world in any application due to its risk of becoming a toxic, persistent environmental hazard.
The landscapes built with this stuff are temporary. But the stuff itself is permanent. As the earth on top erodes away it will be exposed in ugly dead patches like open sores, and eroded itself until it's spread all over the surrounding area as particles mixed with the dirt. But hey, for a hundred years or so some landscape architect's vision of hills will be fulfilled, at a lower cost!
Why is it temporary? The paper the OP linked says "the overall results form the monitoring programme indicate that [geofoam] behaves as expected and that the selected design parameters provide stable and satisfactory structures for long time performance"[1]
It looks more like a national security issue. If we're ever at war then the enemy can always tip over a jug of petroleum ether to turn our deeply embedded geofoam foundations into glue, which I imagine would cause everything built on top to crumble too. It would appear they're mostly building highways using this stuff (rather than skyscrapers) so that shouldn't be too much of a vulnerability but it probably isn't what Dwight Eisenhower had in mind when he built the interstates.
[1] Aabøe R, Frydenlund TE (2011) 40 years of experience with the use of EPS geofoam blocks in road construction. Paper presented at the 4th international conference on geofoam blocks in construction applications, Lillestrøm, Norway, 6-8 June 2011
What is a "long time"? Is it one human lifetime? The time period in which these blocks will be a blight is a whole lot longer than the time period where they make a nice landscape, it's just that the nice landscape part comes first. Should we do anything we want assuming that what happens after we're dead is irrelevant?
I replied to your comment because I agree with you but I couldn't find any information online to support it. I cited research where they studied foam that's been in place for 40+ years and it's fine. I was hoping you had data that would support what we both want to hear.
Well, I find it questionable to build roadway/infrastructure foundations out of something vulnerable to structural degradation from exposure tp petroleum products.
One wreck involving a fuel tanker without sufficient containment and the entire subgrade starts to dissolve and buckle and sink?
> Geofoam producers and boosters claim that geofoam actually reduces the environmental impact of a project by allowing for shorter construction times, reducing the need for energy-intensive earth moving machinery, and reducing the carbon footprint of the overall project.
I guess they forgot about all the machinery and oil consumed by the manufacturing process. Granted, the oil is not being burned but polystyrene is not really environmentally friendly itself either: https://en.wikipedia.org/wiki/Polystyrene
I see the economic and engineering qualities, especially when building whimsical parks and so on (which is a frivolous use case). But I can't help but feel this is a perverse way to build natural landscapes such as parks. Imagine what happens when a burrowing animal finds its way onto one of these things? What happens when you have to dig under the foam in the event you need to do so? What about tree roots? What about micro-plastics? et cetera.
This line sums it up nicely:
> It can come as a shock to realize that giant bricks of polystyrene are stuffed below the turf, like silicone implants under the skin of a city.
Perfect for the Instagram generation: a fake city with fake tits.
Nothing new under the sun. Take a look at Central Park in New York. Almost everything you is is constructed. They dug the ponds and built up the hills. They didn't have geofoam but if they did they would have used it. Look a Tunnel View in Yosemite. It's there because NPS manages the trees below the view to frame it. Hell, the very idea that there is urban space and nature space is something we humans invented.
I think you're not replying to the main (or at least, most important imo) point of the parent: it's that this man-made landscape has now plastic embedded in it, with all the potential risks it entails
For what it's worth, I don't think there's anything wrong with creating (or re-creating) natural spaces. There's no reason to become a nihilist over it.
There are houses built with foam blocks as the form for holding concrete (ICF) built in the 1970s that are still standing.
Make sure the foam used has the proper PSI rating, and make sure you have proper drainage to reduce hydrostatic pressure, and there's no reason these things can't last 'forever'. It's not like the foam is biodegradable after all.
Not biodegradable, no, but it does have this pesky vulnerability to gasoline and other solvents, which turn it into napalm. Thanks to the extremely low density, a little bit of liquid can dissolve a whole bunch of foam. So long as it's well-sealed, there's no problem, but I'm a little nervous when I see it being used to construct highway onramps and the like.
> The other outcome of this streamlined construction process is a reduction in labor. This reduction in labor costs is a boon for investors and project managers, but a loss for the workers that would otherwise be employed for more varied labor over a longer period of time.
I struggle to understand this. Do people who hold this point of view wish we got rid of cars and instead manually carried materials everywhere? Should we ditch earthmoving equipment in favor of shovels? After all, that would employ more people for longer.
This is an instance of the "broken window fallacy". To understand the nature of this fallacy, I highly recommend Economics in One Lesson by Henry Hazlitt [0]. It's short and easy to read.
However, Hazlitt's lesson is not the complete story. The question that Hazlitt does not answer is, what is "the long run", and how exactly do the gains from productivity get distributed to "everyone"? This is likely where a lot of leftists would object to Hazlitt, arguing that it's better to protect current jobs than to let capitalists (or whoever) suck up all the gains for themselves and never redistribute them. You can argue about the semantics of whether it's possible to "hoard" wealth, but ultimately there is some merit to that argument. But the fallacy remains the fallacy, even if wealth redistribution is an unsolved problem.
We use this a lot to support landscaping in the sky (rooftop terraces and such on high rises) which is an architectural trend that really needs to go away. There is nothing green or sustainable about the extra concrete needed to support it.
But the alternative to geofoam is usually clean fill, like sand, which weighs about 110 lb/cf. contractors ask to substitute it because it’s cheaper, but it almost always results in thicker structure and more rebar to support it.
I'm involved with a project using a form of aircrete right now, and we're having a right hell of a time with proper curing and temperatures (to be fair some of that is due to an outrageous spec), as well as mixer truck dwell times, and even input aggregate temperatures. E.G. we had to bring in a refrigerated semi-trailer to store the sand to ensure it was cool enough to make the mix during this heat wave.
We are, in fact, trying to convince the owner to let us put in geofoam in place of the specified aircrete.
It's much, much easier to bring in a trailer of geofoam blocks, place and size them then compared to pouring a lift of concrete and ensuring proper aeration, vibration, temperatures, etc.
If you're not making your own geofoam on site, it seems like the fair comparison should be bringing in a trailer of aircrete blocks made elsewhere in controlled conditions instead of being made to mix it yourself. Any idea why nobody makes them?
Very likely it's just no contractors dealing with it.
I read up on it when we did electronics for concrete mixers.
The chemistry of foam concrete is a very inexact science, bordering on being "possible to get right through talent only"
Very little literature on it, and proprietary foaming agents all come from Eastern Europe with zero info, or instructions beyond "mix this stuff with water 100:1, and pray"
This is pretty rad. Growing up I used to be into model trains and one thing that always blew me away was model train landscaping. You know, those amazing basement setups that recreate the Rockies or insanely detailed recreations of westchester subway yard. One of the main ingredients for building a model train layout is foam. Simply put, you lay foam down and then carve into it the landscape you wish, paint it, and then cover it with fake greenery. With the right setup it cured hard as rock and provides a foundation for the layout to sit upon. Reading this article it seems Sweden is making 1:1 layouts for engineering projects. This, to me, seems like a really great application. What I want to know is, how does it hold up to time, elements, curing, etc in the long run. Fascinating stuff though.
Question for you. When you want to change the landscaping, or say the land is sold and is going to be repurposed... what exactly do you do with all those blocks?
And have you ever had packing material that over time had more and more corners rubbed/ripped off, leaving little foam balls stuck to every nearby surface? Now imagine that orders of magnitude larger scale. I hope you _really_ like little foam stuck to everything.
Usually when you want to change the landscaping you bring out the big knife and cut away. Model railroaders (as the community is called) use pink insulation foam so it's easier to clean up, cut up, carve out. A hot wire foam cutter is then used to shape the new foam blocks to the existing landscaping, paint, and repeat the coverage of false foliage and greenery. The old landscaping at that point goes into the garbage and into landfill after scraping off what foliage you can to save (in little jars) for the next landscape project. Pink insulation foam doesn't have beads like polystyrene Styrofoam does so it's not so much of a mess. Similar to memory foam but harder. I guess theoretically you could shred the pink foam and use it in foam spray to insulate the attic...
In the end, railroaders like XPS foam as opposed to EPS foam due to lack of "beads" and mess.
Geofoam is styrofoam. The "article"is an advertisement. I guess with all the consumables like cups and plates being wound down because of environmental concerns, styrofoam producers are scrambling to rebrand and pivot into other markets.
Styrofoam dissolves in gasoline (in the anarchist's cookbook this was a recipie to make "napalm"). I wonder if this opens up a new venue for terrorism: drill a hole and pour in some solvent or catalyst, watch as the hill collapses...
It’s funny to think of those who would oppose it. There are actually many, like the poster who is concerned about biodegradability. It can’t sequester carbon if it also biodegrades. “Split wood, not atoms!”
> It can’t sequester carbon if it also biodegrades
This is misleading. Trees in a forest store carbon as long as the forest exists. Individual trees might degrade (or be trapped underground), but new ones are born.
And yet all of the sequestered carbon we are tossing into the air in the form of burning fossil fuels was once biodegrading organic matter... it's almost like "biodegrade" and "sequester" can coexist.
Over time, there's no reason it wouldn't. It's expanded polystyrene with an eco-friendly name, and anything that would degrade EPS would degrade these blocks. Groundwater is the big one I'd be concerned about. It being dug up and trashed by future earthworks projects would be the second big thing.
I was really curious about bearing capacity of this material, and I found this spec sheet:
https://my.civil.utah.edu/~bartlett/Geofoam/EPS%20Geofoam%20...
The compressive strength is actually pretty good if you use the high-end stuff. I would be skeptical of the cost-benefit versus other common fills.
I almost spit out my coffee when I saw the section on levees and the anchors "(if necessary)" annotation. I would be very reluctant to market an extremely low-density product as a barrier for flood protection applications. It really makes me wonder about the rest of the statements in the brochure.
That ‘if necessary’ probably proves to be true most of the time, but I think the use case they mention (levees built on compressible alluvial soils) can easily make it the better choice.
Buoyant forces apply to things in the ground. HDPE pipes without adequate backfill or anchoring will float out of the ground, like zombies, in flood conditions where the pipe itself contains air. Your local street department has probably seen it. Also, for expedient flood protection, those tubular dams are typically filled with water.
My reaction is that "if necessary" isn't really an "if". It is necessary, or your levee may float off precisely at the time you need it to work.
> Geofoam blocks can contain some percentage of recycled plastic, and the blocks themselves are marketed as recyclable
So instead of using some of the millions of tons of existing styrofoam waste as landfill they produce brand new styrofoam and put that in there instead? Did I get that right?
The article seems to describe what I’ve always known as styrofoam, and yet the styrofoam I know that appliances come packed in does not have the compressive strength to support cars on a highway. What am I missing?
They're not running traffic directly on a road surface of styrofoam. A picture in the article shows a road embankment under construction, with a rebar mat on top of the geofoam blocks. This will have a concrete pad poured on it, which spreads the load of the road and traffic across the entire area of the embankment vs just point loading of the tires of the vehicles, so it can easily handle the weight.
There are different compressive strength levels available in expanded polystyrene. The stuff under our foundation for example has a compressive strength of 150 kPa. That's over 15 t/m² (>3000 pounds/sqft in medieval units).
I bought a house with a sunken living and wanted to raise the floor. We used blocks of this stuff to fill up the sunken living room, so we only had to use 6" of concrete on top. I was surprised when I found out, but my builder says it is common.
I don't know if I would use this stuff outdoors, though. We had a bean bag chair full of polystyrene balls leak outside, and I was finding the stuff in my yard for years.
Orders of magnitude more expensive. Similarly difficult to remove and manipulate. Nanocellulose aerogel could be a candidate, as most of the processing chemicals can be recovered and reused, and cellulose is abundant, but significant work is needed to give it the same strength and durability to replace styrofoam. In landscaping, it'll also need more treatment against fungus and other things that can eat cellulose.
Rammed earth and other more integrative materials should be more popular, imo. Having crap like this geofoam should be considered completely unacceptable, like using baby blood to mix cement.
Potential toxicity of polystyrene microplastic particles https://www.nature.com/articles/s41598-020-64464-9
"Polystyrene is ubiquitous within sea-surface samples collected from across the globe" https://pubs.acs.org/doi/10.1021/es504525u
Am I missing something?