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Engineer turns plastic into bricks that are reportedly stronger than concrete
- deleted 4y ago[deleted]
- transfire 4y agoSeems to me a great idea!
- throwaway0a5e 4y agoBut is it cheaper? (or could it be) Wood, stone, pretty much everything is stronger than concrete. We use concrete because it's strong enough and cheap (and doesn't rot like wood, but a lot of things don't rot so that's not too novel).
- adhesive_wombat 4y ago> and doesn't rot like wood Unless you get an alkali silica reaction (aka concrete cancer).
- Enginerrrd 4y agoTwo points: 1. The article says its "cheap" for what that's worth. 2. This IS concrete. It's a mixture of sand as aggregate and plastic as a cement AKA binding agent.
- echlebek 4y agoI thought this was pretty cool, but then 50% of the recommended posts are about NFTs, which are a known scam. They are also by the same author as this post. So this tells me the author isn't necessarily looking at things with the most critical eye.
- Isamu 4y ago>Wood, stone, pretty much everything is stronger than concrete. Hang on, compressive strength is very, very high. Tensile strength is much lower so that’s why we add rebar and mesh.
- halffaday 4y agoTypical compressive strengths in concrete mixes for construction applications is often around 3000psi, which is actually about the same as HDPE. “Flowable fill” might be closer to 800-1000psi, which is close to end-grain compressive strength of some common lumber products. Special concrete mixes can be used to get almost 20,000psi, which is a bit less than steel (which has much higher tensile strength). The real value proposition of concrete is that it’s made out of very common materials and can be produced in enormous quantities in most places in the world at low cost.
- keithnz 4y agothey say 25% cheaper than concrete. The video posted in another comment (https://www.youtube.com/watch?v=iFcPqXxAUWM https://www.youtube.com/watch?v=iFcPqXxAUWM) has a lot of details
- legohead 4y agoSaw this on Business Insider on YouTube: https://www.youtube.com/watch?v=iFcPqXxAUWM https://www.youtube.com/watch?v=iFcPqXxAUWM
- keithnz 4y agoThat's great, this is a much better explanation with a lot more details and what they are targeting the bricks towards.
- iancmceachern 4y agoThis is brilliant. It's like asphalt, which is just concrete (cement, sand and lime) with some of the cement replaced with oil/tar. This is that same idea but using plastic not oil/tar. Truly brilliant. It's a new type of composite building material.
- SCAQTony 4y agoThe bricks will aspirate toxic chemicals when exposed to direct sunlight: "...Plastics leached twice as much pollution in sunlight as in darkness, they found. One bag leached 263 different chemicals in the dark but more than 13,000 when exposed to light! Others leached even more. And the longer bags were exposed to sunlight, the more chemicals they leached. ..." https://www.sciencenewsforstudents.org/article/everyday-plastics-pollute-leaching-thousands-chemicals#:~:text=Plastics%20leached%20twice%20as%20much,the%20more%20chemicals%20they%20leached https://www.sciencenewsforstudents.org/article/everyday-plas....
- iancmceachern 4y agoThey could paint them once installed, like nearly every building on the planet. Simple problem, simple solution.
- jerrysievert 4y ago> They could paint them once installed, like nearly every building on the planet. Simple problem, simple solution. perhaps with a lead paint! that'll make everything better. "sealing" a toxic material is not a solution when that seal can be broken by scraping it. let's face it, this is a toxic material that doesn't belong in our homes or our society.
- iancmceachern 4y agoThen get rid of everything plastic you own.
- 4y ago
- learndeeply 4y agoWhen the concrete weathers, will the plastic in the bricks turn into micro-plastic?
- Tagbert 4y agoIt will break down much more slowly as a solid object than as separate pieces of plastic. It will likely be painted or covered with a facing anyway.
- jahewson 4y agoQuality weatherproof paint is expensive and needs to be maintained. That’s going to have an impact on the cost. Plus if you ever want to modify the building you’ve got an environmental hazard on your hands.
- zionic 4y agoYes, which is why this is a bad idea.
- bragr 4y agoAlmost certainly.
- penneyd 4y agoThe plastic has already been produced, so it's already an environmental problem, this repurposes it, one way or another it's going to break down and end up somewhere.
- shadowtree 4y agoThis is a great way to get microplastic through abrasion into even more places within the foodchain. Wonder if it burns nicely too, plastic after all is "frozen gasoline" - here mixed with sand. /debbiedowner
- hh3k0 4y agoThat's where my mind went first, too. We don't need more plastic in our lives, quite the opposite actually.
- yarg 4y agoIt could be probably be mitigated with some sort of coating. It would be more expensive, but it would still allow for the repurposing of waste plastic.
- moffkalast 4y agoAh I know, coat it in epoxy!
- 2muchcoffeeman 4y agoThere must be some applications though. Perhaps in the initial foundation which is probably waterproofed and underground? Or internal partitioning walls that get painted or plastered over?
- bragr 4y agoI bet sourcing all that sand will be a bigger problem than they expect as sand is a rare and nonrenewable resource that's heavily in demand for concrete and sourcing it has all sorts of environmental issues of its own. They should look into replacing that with something that's also cheap waste. Maybe crushed glass would work?
- ProtoMathics 4y agoglass is made from sand, there is less glass in world then sand, and again, why lock more precious commodity in another product which we are already making from other less precious commodity ?
- max599 4y agoIt's the shape of the grains of sand that's bad for concrete, not the chemical composition. It gets less angular and more round when it moves in the desert and it doesn't bound well with cement. Sand that is good for concrete is rare and making it is expensive. The "bad" sand that is common everywhere is still perfect to make glass.
- Dylan16807 4y agoCertain shapes of sand are rare compared to global construction, sand in general isn't. Unclear what this method needs.
- once_inc 4y agotwenty-five percent of Africa is literally covered in sand. Sand comes in different granularity and compositions, but for concrete this is often irrelevant.
- formerly_proven 4y agoActually it matters quite a bit. That's why countries which are literally filled with desert sand import river/sea sand for their construction. Finding a way to make desert sand usable for construction concrete would be significant.
- ProtoMathics 4y agoProblem is, plastic can be "dissolved" and then recycled, so why lock precious commodity as plastic in bricks for decades ?
- blangk 4y agoI'm not sure what your argument is here - they are recycling waste plastic to have commodity value as a building material already
- advisedwang 4y agoThat's only economical for a small fraction of plastics, we are sending a huge amount to landfill right now. The bar for turning into brick could well be smaller, in which case it could be done with plastic which would otherwise go to landfill.
- xwdv 4y agoGood food for those plastic eating bacteria that will inevitably be released into the world.
- aaaaaaaaaaab 4y agoNot so great. Plastic is going to be seen like asbestos in 50 years.
- dijonman2 4y agoCitation?
- echelon 4y agoWhich deadly diseases has plastic been linked with? Is the endocrine content of BPA any worse than drinking soy milk? Bioaccumulation of microplastics may be a different story. It may pose an inflammation risk, serve as a safe harbor for bacterial colonies, or be carcinogenic, but as far as I'm aware there haven't been any studies showing this.
- armitron 4y agoBecause we need studies (ideally, funded by the same corporations that poison us) to tell us that having increasing quantities of plastic in our blood, lungs and other organs is bad. What happened I wonder to the precautionary principle? Maybe that's going to be our collective lamentation when we crash at warp speed into some sort of great filter.
- echelon 4y agoI get the skepticism, but reality is complicated. Plastic saves lives, conserves energy, and makes the economy faster and better. Outright removal will be nothing short of impossible. Consumers don't want to be inconvenienced. Starbucks couldn't even keep non-plastic straws on without a massive amount of customer complaints. Plastic alternative materials science has a long way to go to even meet the same needs. There are some interesting developments with wood and ceramics, especially in the building world, but plastics are and were nothing short of a miracle. Unless the number of deaths directly attributable to plastics crosses some alarming threshold, nothing will be done. People would rather go about their daily lives. It's kind of like how people continue driving cars, flying, and using coal-fired electricity despite being warned of global warming. It's not going to change until people really feel it and demand it. They'd rather keep using their iPhone and read about the issue on Twitter.
- blblb123 4y ago
- cyral 4y agoAsbestos is just a natural mineral they said...
- robinsoh 4y agowhich Canada had long banned for internal use but only stopped exporting it last year to 3rd world countries after an international outcry. I can't remember if there's still some exemptions or loopholes they're using to continue to use.
- wardedVibe 4y agolead is just a metal... Microplastics can be much smaller than sand, and may play a role in persistent inflammation*, though really, we just don't know yet. The safe default assumption is maybe don't spill massive quantities of a completely novel compound into the entire biosphere. Its an action we can't undo and will have implications for generations. * https://www.sciencedirect.com/science/article/pii/S0048969719344468?casa_token=ff9eXDNRiIQAAAAA:Xb6-UWf1ML0cPuvOdytyHOP6lN6qdtAjG9cTyz9BK9bXfS_HjDkh9l2nbfQJj7qoJhhTItt0HPk https://www.sciencedirect.com/science/article/pii/S004896971...
- blblb123 4y ago
- kaetemi 4y agoCan they be recycled, or is it another dead end? Trash brick projects are popping up every few months or so. It seems more like a cheap filler material than a sustainable product.
- jazzyjackson 4y agoif it's a brick, couldnt you recycle it by using it wherever else you need a brick?
- Vladimof 4y ago> if it's a brick, couldn't you recycle it by using it wherever else you need a brick? that's re-use and that's even better then recycling
- scythe 4y agoUnfortunately I think that the frequency of stories like these happens because people incorrectly assume that plastic is cheap and plentiful. I learned this because of a paper about remarkable properties of an alumina-PMMA composite: when I investigated the material costs, I learned that PMMA (aka acrylic) was more than half of the price, even though it was only 20% of the composite by weight. Plastic has always been a suitable building material. But it's expensive to produce in bulk. It just happens that a fraction of a gram of polyethylene can still make a useful grocery bag, which leads to there being a lot of small pieces of plastic scattered all over the world. As a method of waste management, this could prove useful. But 500 metric tons of plastic bricks per year (the supply of waste from the article) will only build a few houses, and won't make a noticeable dent in the demand for building materials in Nairobi, a city of millions. The most interesting variant of polymers in construction I've heard of is the use of fiberglass-reinforced polymer rods as rebar in reinforced concrete. This should be more corrosion-resistant than steel, allowing reinforced concrete structures to last longer. This allows you to use smaller amounts of plastic to make larger amounts of buildings.
- colpabar 4y agoDo people of color ever roll their eyes at websites like this? Does it ever just seem silly? edit: I am white, and my question is not for white people. I call it “peopleofcoloronhackernews” :^)
- skizm 4y ago"POCIT" was too good of an acronym to pass up on.
- balls187 4y agoNo. It's nice to see positive stories being highlighted.
- kenjackson 4y agoIt’s a little on the nose, but the point is to be an example for other people of color. An illustration that this type of work can be done by “us”. What I don’t like is when the claims are needlessly exaggerated.
- colpabar 4y agoI can understand that. I just can't not draw the comparison to the way we segregate sports by sex, since males are generally bigger and stronger than females, and I wonder if any POCs see stuff like this in a similar way. And to clarify - I am not suggesting there is any similarity to that and intelligence, I am just pointing out that websites like this sort of make it seem like that's the case. Please don't assume this is racism, I am here to gain perspective about something I don't understand.
- drc500free 4y agoIt seems like you want them to. Why is that? I would think a good number of under-represented people would be interested and maybe inspired.
- colpabar 4y agoI'm genuinely curious what they think, because I am not one, and yeah websites like this do seem kind of silly to me. My question was also for them, and I'm guessing since you said "them" and "I would think", you are white, so why are you responding to it? I understand the intention; I am asking about the actual effect.
- astatine 4y agoMixing plastics with asphalt has been tried for roads in India for many years now. There is one stretch near where I live which was done 10+ years ago. There is an official policy on trying this, as a pilot, for any agency that wishes to use it. See: https://www.prakati.in/use-of-plastic-for-road-construction-in-india/ https://www.prakati.in/use-of-plastic-for-road-construction-... The road which I use occasionally seems reasonably good as roads go. Unless you see the boards informing users about the mixing of plastic you wouldn't know.
- lelandfe 4y agoI think plastic probably makes more sense as a construction material than for roads. Cars are really tough on roads. I have to imagine that plastic in roads would get shredded into microplastics and wind up all over the place.
- at_compile_time 4y agoTires and brakes already do that. This would just do it more.
- metadat 4y agoNot "just". More, more, more microplastics.
- virtue3 4y agoasphalt is already tar/oil anyway, wouldnt make up that much of a difference I'd think.
- martyvis 4y agoIf it is an organic compound it is probably going to breakdown in years or decades. (Crude oil spills AFAIK only have a relatively short term impact). Most plastics seem to take centuries before they are back to something that is less noticeable in the environment.
- FunnyBadger 4y agoThat's nice except bricks are NOT interchangeable with concrete in 90% of building cases.
- mjh2539 4y agoBut is its coefficient of thermal expansion roughly the same as rebar?
- Animats 4y agoI think I've walked on such a material. I was walking on a sidewalk for which a few squares felt squishy. They looked like concrete with a lot of gravel, but had much more resilience.
- EamonnMR 4y agoMight have been shredded-tire playground walkway material.
- Animats 4y agoNot that soft. It looked like rigid concrete, but sagged a bit.
- colpabar 4y agoMaybe the foundation below the bricks was a bit unstable?
- throwaway742 4y agoWas it in Detroit? https://jalopnik.com/a-detroit-bridge-collapsed-under-a-mans-feet-sending-h-1848937950 https://jalopnik.com/a-detroit-bridge-collapsed-under-a-mans...
- jazzythom 4y agoDidn't I just read about an engineered enzyme to break down metric tons of plastic waste? You can’t have both these futures. Because your roads will melt and buildings will collapse. There needs to be some coordination or authority
- hardwaresofton 4y agoWe absolutely can have both of these futures -- if people use the right tool for the right job and both of these tools can coexist (even if not used in the exact solution). Also roads may just be the first use case for this technology but new thinkers and new people will find new usecases.
- jazzythom 4y agoWhat about the malicious actors in the crowd? This is an asymmetric vector with significant latency
- whynotminot 4y agoA malicious actor could also dump termites on your lawn, start a fire, throw a rock through your window, etc. What you bring up is a point for the police to investigate, and maybe a few more lines in your insurance policy to cover. If you’ve made an enemy, it doesn’t really matter what your house is made of.
- jazzythom 4y agoHow about a billion dollar bridge?
- whynotminot 4y agoThen maybe not? I’m guessing there’s a lot of risk analysis that goes into building billion dollar structures.
- 4y ago
- braingenious 4y agoI have a buddy that’s going into CU Boulder for material science soon! It’s such a cool area of study, it must be fun to work with stuff like this. I’m interested in how these bricks work out in the medium to-long term though. Things as “simple“ as bricks usually end up being unfathomably complex in practice. Cool idea though!
- sigstoat 4y agopreviously on hacker news: https://news.ycombinator.com/item?id=26093535 https://news.ycombinator.com/item?id=26093535
- _Nat_ 4y agoLooks like a story about someone trying to recycle plastic by using it as an ingredient in [polymer-concrete](https://en.wikipedia.org/wiki/Polymer_concrete https://en.wikipedia.org/wiki/Polymer_concrete ). As for polymer-concrete's history (https://www.sciencedirect.com/science/article/pii/B9781845692636500122 https://www.sciencedirect.com/science/article/pii/B978184569... ): > The history of the research and development of polymer concrete is relatively short compared with that of conventional cement concrete. The early research and development of the polymer concrete was done mainly in the Soviet Union (currently, Russia),1 the United States,2 Germany3 and Japan4 in the late 1950s to the early 1960s. The idea of making polymer-concrete with recycled-plastic has also been around. For a random review article (https://www.sciencedirect.com/science/article/pii/B978085709424750013X https://www.sciencedirect.com/science/article/pii/B978085709...): > Abstract: [...] The volume of polymeric wastes such as tyre rubber and polyethylene terephthalate (PET) bottles is increasing at a fast rate. [...] The majority is just landfilled. This chapter reviews research published on the performance of concrete containing tyre rubber and PET wastes. Furthermore it discusses the effect of waste treatments, the size of waste particles and the waste replacement volume on the fresh and hardened properties of concrete.
- mr_toad 4y ago> The history of the research and development of polymer concrete is relatively short compared with that of conventional cement concrete. This history of most things is short compared to concrete. https://en.wikipedia.org/wiki/Roman_concrete https://en.wikipedia.org/wiki/Roman_concrete
- SentientAtom 4y agoPlastics are polymers that are vulnerable to UV degradation resulting in the production of microplastics. This has no application in direct sunlight PERIOD.
- betwixthewires 4y agoToo much about the award and background and whatever and not enough about the bricks.
- shetill 4y agobrace yourselves for lego houses
- yummybear 4y agoGreat, but doesn't using plastic for surfaces exposed to a great amount of wear and tear, add to the microplastic problem?
- qayxc 4y agoNot more than the plastic waste the bricks are made out of. In fact, this should reduce the problem since in brick form, less of the plastic is exposed to the elements as opposed to the plastic waste it's made out of.
- koreanguy 4y ago
- dusted 4y agoGood old reportedly.. Also, seing how we're only now starting to investigate the effects (and amounts) of microplastics in the environment, it might not be entirely unreasonable to not start building giant structures of it just quite yet ?