Hacker News Reader

Comment by lmilcin | Hacker News Reader

Just because the brick is able to withstand throwing it on the rocks doesn't mean it is not going to deform under load.

Brick strength is measured in ability to withstand deformation under load and as far as I know there isn't any popular "plastic" that can do comparably.

For a single story house this probably doesn't make any difference, but for a larger structure the load could cause bricks to loose shape, creep and cause the structure to fail.

Also, plastics tend to get soft rapidly at temperatures. I don't think plastic bricks exposed to sun (Kenya?) would fare for long.

Another issue is that plastics tend to deteriorate in UV. That could be fixed with a good paint but it also costs.

(Edit: for the pavement this is horrible idea as the plastic is going to be broken down and dispersed in environment in large amounts)

View on HN

> ...this is horrible idea as the plastic is going to be broken down and dispersed in environment in large amounts

This take seems trivially and obviously wrong. Recycling plastic produces a lot of nasty chemicals and is awful for the environment, but we still do it, because the alternative (chucking it in a landfill) is worse. The question is not whether these plastic bricks are bad in absolute terms, it is whether they're worse than whatever was being done with Kenya's plastic waste before this woman came along.

However, it is curiously common. From elsewhere in this thread:

> What about leaching [sic] chemicals into the soil and groundwater?

> I do wonder about microplastics flaking off of them, though....

> ...making me concerned about plastic particulate being released...

> What happens when these erode - wouldn’t plastic particles contaminate water?

> ...how does this product not heavily pollute the environment?

Isn't that interesting? Not to sound preachy, but did anyone have the "wait isn't this bad for the environment" reaction to any of the other stories on HN today? Starlink? That new Samsung fab plant? Shit, there's an ad on the front page right now for a gourmet dinner delivery startup. What is it about this one that brings out HN's inner environmentalist?

> What is it about this one that brings out HN's inner environmentalist?

This is obvious and very easy to see, while the other examples you brought up aren't. Your examples might even be doing more damage, but because the end result is shiny, people are distracted.

Plus, I'm sure there's a part of first world vs third world prejudice: "she's probably uneducated and doesn't know what she's doing, plus her accent sounds that way".

>Not to sound preachy, but did anyone have the "wait isn't this bad for the environment" reaction to any of the other stories on HN today? Starlink? That new Samsung fab plant? Shit, there's an ad on the front page right now for a gourmet dinner delivery startup. What is it about this one that brings out HN's inner environmentalist?

This is one aspect of the tech world (and more broadly the "comfortable knowledge worker" class) that irritates me. There are so many aspects of sustainable development that are only considered from a perspective of NIMBYism mixed with orientalism. The one that bothers me the most is the portrayal of overpopulation as something caused only by people in developing countries, as if the first world wasn't part of the total count.

Plus, the first world inhabitants pollute much, much more than third world individuals. Plane travel, consumerism, person/car ratio, etc etc

Oh “first” or “third”, this is actually the “only one” world we have. The more we want to be rich, the more we destroy it. ...how many want to be rich?

What is rich actually? I still don't understand how can an entire nation be rich without someone (immigrant) or machines doing your job.. or access to latest gadgets? but i still see people struggling to pay for education, finding jobs is extremely difficult etc.. people are still low/middle/upper irrespective of the country. there are several developing nations where people don't have so much struggle to live.

> Plane travel, consumerism, person/car ratio, etc etc

The rest of the world is catching up faster than most people are aware.

Here's a link for daily plastic waste generation per person: https://ourworldindata.org/grapher/plastic-waste-per-capita

I don't see an obvious correlation between first world and amount of waste: the #1 country is Guyana, China and Russia are well above Canada, etc.

Similar with CO2 emissions: https://www.worldometers.info/co2-emissions/co2-emissions-pe... The #1 is Qatar, we in Montenegro are on the second place.

Yes, there isn't a clear divide between "first-world" and everyone else anymore. That being said, I think the wealthier countries that are more industrialized have a debt to pay with regards to climate impact given that they were able to develop and build before mainstream awareness of the issue, and virtually all of the accumulated pollution today is therefore due to these industrialized nations.

I'd like to see a period in which China, India, and smaller nations are able to use more than their share of the global quota while the wealthier countries in western Europe and North America use less, per capita and in sum.

The one that bothers me the most is the portrayal of overpopulation as something caused only by people in developing countries, as if the first world wasn't part of the total count.

FWIW if you ignore immigration, nearly all first world countries are gradually depopulating. https://en.wikipedia.org/wiki/Sub-replacement_fertility

Of course, that doesn't mean for a second that the solution to the world's problems somehow involves population control in developing countries.

In fact, birth rate decreases after a certain level of development. The first world went through the same process, the developing world today is going through that process much more rapidly.

So the solution is probably to help them develop ASAP.

> So the solution is probably to help them develop ASAP.

There are two kinds of mythologies that have been the cause of reckless and thoughtless procreation leading to overpopulation: 1. Religion 2. ‘Abundance’ mythologies penned by the Peter Diamandis/Steven Kotler ilk.

I have no idea who Peter Diamandis/Steven Kotler are but I doubt they had any large effects on the overpopulation of the world.

Regarding "religion": do you think "religions" came up with the concept of having a lot of children?

You don't think it's simply a natural instinct, like in all other animals? And that in a world where few make it to adulthood, people tried to have more children?

> And that in a world where few make it to adulthood, people tried to have more children?

It's pretty well-established that it isn't poverty per se but gender equality that predicts birth rates.

I'm not sure what your point is here. I simply mean that e.g. during the stone age most children died early, so you needed to have more of them.

Then I obviously misunderstood you, sorry for the confusion.

Genuinely interested, could you share some academic literature on the subject?

The newest I immediately remember is this: https://www.demographic-research.org/volumes/vol40/2/

Here is a blog post of the author in case the above is not readable for you: https://www.niussp.org/article/gender-equality-and-fertility...

This study is in the context of previous assumptions of a U-curved relationship: low equality == high birth rates, medium equality == low birth rates, high equality == high birth rates. That study shows that the last part doesn't seem to be true.

Thanks!

Poverty can probably actually lower birth rates by forcing women into the workforce. If a parent is at home, the marginal cost is a lot lower for another child than it is if people are paying for childcare.

Direct correlation of female workforce participation and poverty shows no trend: https://ourworldindata.org/grapher/female-labor-force-partic...

The macro trend of poverty <> birth rates points in the opposite direction: https://en.wikipedia.org/wiki/Income_and_fertility

Data points on the very poor end are all over the place, though.

The high workforce participation -> low birth rate correlation is definitely visible over time: https://ourworldindata.org/grapher/fertility-and-female-labo...

> Of course, that doesn't mean for a second that the solution to the world's problems somehow involves population control in developing countries.

Why not? A lot of people on the left are saying that having children is bad for the environment, why shouldn't this be true in poor countries?

Because A doesn't automatically follow B.

Fewer children is better for the environment; that doesn't mean one has to favor population control. It's easier, more democratic and probably at least as effective to enforce equality for women in education and economics, and the lower birthrates follow automatically.

Population control doesn't have to mean forced mass sterilizations. If you educate people with at least the partial goal of them having fewer children, that is also population control.

Not that there's anything particularly democratic about "enforcing equality" in foreign countries.

How do you reverse it when it becomes a problem? If we’re taking the long view here, our future generations may be facing a world where there aren’t enough people. Or is that a problem that we’ll leave to them to figure out?

>our future generations may be facing a world where there aren’t enough people

That would be wonderful because it would mean that workers get fair wages. Lack of productivity can be compensated by automation.

>How do you reverse it when it becomes a problem?

That's biologically impossible. Even if you sterilize every human with a birth certificate on earth.

I’m not personally advocating for population control, just couldn’t understand why it would be completely off the table in poor countries.

I think the conversation is just scary for obvious reasons based on human historical tendencies. The topic is not exactly verbotten, but it is genuinely hard to argue for or against dispassionately. Part of the official reasoning is that young population is a poor's country resource. I personally take issue with nations seeing their population that way, but it is not unusual.

I honestly am not sure education is the answer. Both me and my wife are educated. There are arguments against us having children from genetic standpoint and she still wanted to roll the dice. It may work in aggregate, but natural pull is very strong.

Actually that wouldn't be a very efficient solution because pollution is not evenly divided across the world's population. See this map [1] showing CO2 emissions per capita, or this diagram [2] showing CO2 emissions per fertility.

As this article [3] (unfortunately not in English) aptly puts it: "Air travels represents around 5% of the emissions of humanity [4], but 90% of humans have never taken a plane." (the 90% figure is arguably difficult to assess [5]. It comes from an article in French behind a paywall, but other sources [6] show similar numbers).

Finally, CO2 is of course not the only source of pollution. But this map [7] showing meat supply per person shows a similar direction.

[1] https://upload.wikimedia.org/wikipedia/commons/a/a7/CO2_emis...

[2] https://www.gapminder.org/tools/#$state$time$value=2014;&mar...

[3] https://medium.com/enquetes-ecosophiques/d%C3%A9mographie-et...

[4] https://core.ac.uk/download/pdf/30987495.pdf

[5] https://www.quora.com/What-percent-of-the-worlds-population-...

[6] https://www.theguardian.com/business/2020/nov/17/people-caus...

[7] https://upload.wikimedia.org/wikipedia/commons/e/ed/Meat_sup...

Because your children will pollute and consume an order of magnitude more than poor children. If you're American, your children will pollute and consume twice as much as even Europeans, IIRC.

Of course, this is the average American, which is a deceptive number when talking about countries with high levels of wealth inequality.

Please don’t assume I’m American; anything but that.

I’m not an advocate for population control, but if I were I wouldn’t exclude poor countries from my scope. Many poor countries are “developing” and it seems more reasonable to ask people that were planning to have 8 children to instead have 4 rather than targeting people that were aiming for one or two. Especially when the 8 kid family to be is already poor.

The "twice as much as even Europeans" is even more deceptive as there's a difference of at least a factor of 2 between countries in Europe. For instance, Switzerland's consumption of carbon per capita is almost 3 times that of Bulgaria or Portugal, while Luxembourg is apparently over twice as high as the US (not sure why?).

https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...

Yes about Bitcoin and it was a rather large discussion too.

> What is it about this one that brings out HN's inner environmentalist?

Because the project is literally about plastic pollution solving?

Plastic is so cheap any recycling project faces either an environmental or an economical showstopper. I am glad this one is having some impact.

Iirc, plastic wastes are added to the tar mix to cover roads, to saw dust and glue to produce composite deck boards, etc. I am not informed enough to have an opinion on whether it’s a good or bad thing.

One possible explanation is that this has an obvious environmental aspect. If somebody is doing something for environmental reasons, it doesn't seem surprising that people are thinking about it from an environmental perspective.

Obviously many things not done for environmental reasons have environmental impacts, but the mere idea itself doesn't automatically invoke that perspective. You can read about a new fab without thinking about the environmental aspects, but you probably cannot read about somebody recycling plastic without thinking about the environment.

That’s called letting the perfect be the enemy of the good. The perfect doesn’t exist in this case.

the alternative (chucking it in a landfill) is worse.

How so?

hehehe, I knew someone would challenge that. I don't know the particulars, I am inferring that recycling plastic is better than dumping it in some way from the fact that it's more expensive yet people still do it. I did not mean it in the sense of "I know a lot about plastic recycling and ready and willing to defend the mainstream view against people who think it is misguided."

> I am inferring that recycling plastic is better than dumping it in some way from the fact that it's more expensive yet people still do it.

There is a lot of demand to be told that when you separate your plastic out, it gets recycled. There's no demand for the recycling to actually happen, so mostly it doesn't.

> This take seems trivially and obviously wrong.

I don't think this is obviously wrong at all. Dispersing a fine mist of micro plastics into the environment, where it can enter the air and water system, is very very different than sticking a piece of plastic into the ground, where it will comfortably sit for a thousand years with minimal decomposition.

For a good example, here's [1] a study about how car tires, which slowly disappear into the environment, are a major contributor to micro plastics in the ocean.

[1] https://www.nationalgeographic.com/environment/2019/09/tires...

You’re missing that not all plastics make into a landfill and are around us already leeching microplastics. I’d think that bricking them and covering them with other materials would lock them in better than a bottle floating in a river

I lived in Kenya. Stuff under the road doesn't stay there long. They get incredible abuse and little maintenance. It's hard to think of anything that would generate more microplastics than putting it in a road. Plastic in the ocean, in your garden, in an animal's mouth, anywhere else, just can't compare to the grinding action of thousands of cars daily.

The road? These are footpath pavers.

He obviously didn't read the article.

Footpath state in Nairobi is awful, I haven't spent much time out of the capital.

But if you're able to collect those plastics it would be better to send them to a well managed landfill rather than make them into bricks.

Nobody is recommending that we throw used plastic in the river as an alternative.

> Dispersing a fine mist of micro plastics into the environment

Huh? I don't see anything in the article to suggest this is happening...?

Why would you require the article to suggest this? It’s an uncontroversial consequence of subjecting plastic to a continuous barrage of abrasive forces.

Similarly, if rain is expected, I don’t need the forecast to tell me that rain makes clothes wet.

How does their use in footpaths subject the pavers to a "constant barrage of abrasive forces"?

People will step on the path when they are walking on it. Rubber wears down paths, as does any sort of abrasive sand or rocks between the shoe and the road. There is a significant amount of wear even on stone paths from foot traffic. There are some plastics I would be willing to try, like UHMW, but wear resistant plastics like that are also very slippery and not cheap even in recycled form.

She is essentially making composite decking but in brick form. The sand filler will probably take a lot of the wear. Solid blocks of plastic last a long time so the degradation will be minimal compared to the waste plastic it is being made from.

> with minimal decomposition.

That's the thing - does it actually decompose at the same rate or slower than eg. concrete or brick?

Concrete and brick are a natural, inert, substances that have been present, in some similar form, in nearly all bodies of water, and most natural enviromnents, since the beginning of life. Plastics have been around for 113 years, and they don't quickly remove themselves from the water ways (they're buoyant), as rock dust/sand does.

The rate of decomposition is not the correct metric to look at, in this context.

When I visited Kenya, people literally just burned their plastic trash in a pit on the side of the road.

So yeah, any form of reuse/recycling seems better than that.

> the alternative (chucking it in a landfill) is worse

Why is that worse?

Plastic is made out of oil. It belongs in the ground.

So if the rate we produce new plastic is slower or the same as decomposition, than it will be a lesser problem than its today?

> Recycling plastic produces a lot of nasty chemicals and is awful for the environment, but we still do it, because the alternative (chucking it in a landfill) is worse

Manority of plastic waste is NEVER recycled. Lets not spread myths.

There is no need for myths when you can rely on powerful euphemisms such as "thermal recycling"...

"Officially, Japan recycles 84 percent of the plastic it collects, one of the highest rates in the world, but the government designates three types of recycling processes: material, chemical and thermal. Material recycling means the plastic itself is reprocessed into new plastic — PET bottles, for instance, are made into new PET products. This is probably the image of recycling that most people have. Chemical recycling means that plastic waste is broken down into its constituent components, which are then recombined to make new plastic materials. Thermal recycling means that the plastic is burned in incinerators to produce energy."

https://www.japantimes.co.jp/news/2019/07/06/national/media-...

Burning plastic to produce heat hardly counts as "recycling"...

Incidentally, in Japan, PET recycling is a very small minority of all plastic collected, so it hardly moves the mark even if that part is recycled in plastic-loving Japan.

Isn't that interesting? Not to sound preachy, but did anyone have the "wait isn't this bad for the environment" > reaction to any of the other stories on HN today? Starlink? That new Samsung fab plant? Shit, there's an ad on the front page right now for a gourmet dinner delivery startup. What is it about this one that brings out HN's inner environmentalist?

Thanks for bringing this up: Honestly, that thought has never crossed my mind when thinking about these initiatives. Much appreciated: You've changed the way I think.

> This take seems trivially and obviously wrong.

Quite the opposite actually. Tires are already a huge source of microplastics pollution. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664766/

> because the alternative (chucking it in a landfill) is worse.

The problem is that landfills aren't living up to their names. They aren't being filled in and buried. Burying plastic is the best thing you can do to dispose of it. It's only when they're left in the open air to break down and be spread all over the oceans by wind that you have a problem.

> Not to sound preachy, but did anyone have the "wait isn't this bad for the environment" reaction to any of the other stories on HN today? Starlink? That new Samsung fab plant? Shit, there's an ad on the front page right now for a gourmet dinner delivery startup. What is it about this one that brings out HN's inner environmentalist?

The others aren't claiming to be an environmental solution so it doesn't get looked at under that lens first. Plastic as well strikes a nerve by hitting upon other issues like microplastics and past deception of recyclability.

I think it essentially hits a lot of "bad idea flags" combined with a cognitive bias I noticed. A company which casts itself as "pro-worker" company paying $12/hr for say sign-turner jobs when most in the field/area pay only minimum wage getting more backlash than everyone else. didn't "betray them" in spite of paying higher than everyone else. It seems everybody hates hypocrisy in which they are not a participant.

Because this article specifically deals with the environmental impacts of plastics and how to reduce them. Starlink could raise hundreds of moral/philosophical issues, it would be insane to address them all every time.

If the starlink article involved how much plastic waste they caused the discussion would be around that, if it involved privacy and surveillance we would talk about that, if it involved how fast the speeds are we would talk about that...

5 of the 6 points noted in OP’s comment had to do with brick’s rigidity and compressive strength. 1 point was related to the environment. Plastic bricks are an alternative to sand/clay bricks.

Traditional bricks first appeared in China and have been adopted and used by humans across various civilizations for thousands of years.

As engineering advanced globally, the pros and cons of bricks have been well explored and well understood. Plastic bricks are a new contender to this problem.

That said, when you have a new contender to a centuries established and globally adopted solution, it might be more likely to prompt exploration of its potential cons.

Starlink is a new engineering solution with several of its own cons that have been reported in HN. It is difficult to compare Starlink against other alternatives when Starlink has a narrow use case that it particularly excels in (high speed Internet to unserviced areas of the globe)

> Recycling plastic produces a lot of nasty chemicals and is awful for the environment, but we still do it, because the alternative (chucking it in a landfill) is worse.

Is it, though? Or was that just a scam to keep us buying plastic shit and to keep packaging unregulated?

It is not trivially and obviously wrong that it might be better to throw plastic into big holes than to spread it all over the surface of the planet. It's not true for nuclear waste. Not to be preachy, but the "at least they're doing something" common sense argument is not good. You have to do the math.

It's quite common for users to jump down the throats of anyone who talks about privacy/encryption without sufficient perceived weight behind them. I suppose this could be seen as more of the same. But I also wonder if the comments would be less dismissive and condescending if the article were framed differently. There's a lot more to this story than the journalist has bothered to cover and they are partly to blame for the reaction.

"Former data analyst and engineer creates startup to develop award-winning material over five times stronger than concrete from waste, following scholarship in US university materials lab."

> What is it about this one that brings out HN's inner environmentalist?

This is the oldest internet comment phenomena in the world, so why do you only notice it here and not every other time?

People always have the nature to attack and knock down, and stories of an individual building something on their own is a far more accessible punching bag than anything else you mentioned. We get to roleplay as critics, scientists, environmentalists, bureaucrats, and we love it.

pg's "middlebrow dismissal" was coined from watching HNers attack the guy building something in his garage.

I only skimmed the article, but I thought they were just pavers. (For making a path).

Buy yes, I came to say something similar, if you just compress the plastic into a block and lay it down to make a path then as it deteriorates surly you are just contaminating your environment with mico-plastic particles.

Ssssh...

People prefer to distribute their problem into invisible pieces put into the environment slowly over 1000 years than to just bite the bullet and incinerate plastics that have reached their usable lifespan...

There are real reasons to not want microplastics in your local environment, but I think your dismissiveness of spreading a problem out over 1,000 years is unwarranted. There is a huge difference between a problem that has to be solved in a year and a problem that has to be solved in 100 or 1,000 years, because time is an incredibly valuable asset.

Delaying some of the carbon we put in the atmosphere for hundreds of years is massively useful, because it buys us time to try stave off and ameliorate some of the effects of climate change.

Fair but you can also simply bury the compressed bricks yeah? Recycling plastic has always been a ploy by the oil industry to increase consumption and make people feel good about the product.

Burying the compressed bricks is actually a great way to handle sequestration.

[1] https://www.npr.org/2020/09/11/897692090/how-big-oil-misled-...

well, that pretty much describes a landfill.

I've always wondered if they couldn't compress it, like those bricks but cubes, then use those cubes mixed with base fill dirt for building bridges and such. Like the massive earthworks they build around highways and such.

This isn't a ploy, it's a feel good puff piece about someone finding a use for the wasted they're swimming in.

A plastic paver walk way is nicer than a muddy path littered with plastic refuse.

I didn't suggest this was a ploy, I'm confident that the person in question has only the best intentions. I don't think it's unfair to step back and ask what the right approach is, intentions aren't always enough.

For instance, the issue with flammability/melting and also microplastics contamination is real and worth asking. I wonder if using these bricks as building foundations or something might not be a good way of solving both problems at once. However, that's an idea that would only arise if we ask pressing questions in the first place.

It's not the ideal building material and it's a plentiful resource that would otherwise end up ideally in a landfill but likely along the side of the road.

From their perspective it is a good use of something that might otherwise be litter.

Sure, the climate change problem is eased. Microplastics in the environment though are a totally different problem & having it slowly accumulate over thousands of years is actually worse because it's a tragedy of the commons scenario. Cleaning this up in 100 years is going to be far more expensive than forcing companies to deal with the trash properly now. Moreover, it's not the companies that end up paying for such a problem but the rest of us because they've externalized the problem (see all the superfund sites in the USA that are chronically underfunded).

Individual micro plastics don’t last that long. The vast surface area to volume ratio speeds up how quickly even durable plastics break down.

Well, unless you start inhaling the plastic dust from plastic road.

I am pretty sure that, even if not "forever chemical", the plastic dust will outlive your lungs.

In 100 years this will be the least of our problem. Either because it will be trivial to solve by then, or because we will be extinct or perhaps involuntarily returned to a pre-industrial life.

Why would we be extinct? This ridiculous eschatology doesn't belong here.

It's not at all ridiculous if you pay closer attention to various historical events. Maybe the biggest shock in this regard would be the Cuban Missile Crisis. We generally remember just a tense moment followed by the installation of red phones, but a even cursory look at the detailed timeline of events and the sheer number of near misses and gross errors is enough to make the hairs stand up on your neck and question your inductive reasoning.

Now with the unknown prospect of increased weapons development over a century, it gets even less ridiculous. Imagine the international quagmire where something worse than nukes exists, but with a much easier manufacturing process.

In any case, my exact argument isn't that extinction is the most likely scenario. Just that the least likely is one where we are just chugging along with the same overall technological capabilities. Worrying about what will happen to micro-plastics in a hundred years is like a New Yorker worrying about the growing quantity of horse manure in the city circa 1894.

well, imagine living in 1850 and someone telling you that 100 years in the future, ancient organic goop will allow millions of metal devices to tirelessly labor on behalf of their owners, some of these machines fly across oceans, and some can drop explosives that can annihilate entire cities

Twenty Thousand Leagues under the Sea was written in 1870 and features a nuclear submarine (kind of).

'The best solution to pollution is dilution'

Why do you advocate for CO2 pollution? Capturing that CO2 suffers from the exact same problem. You either pump it into sealed caverns and hope they don't leak or somehow extract the carbon and turn it into a solid. In the end you are "landfilling" the CO2 instead. Why not skip the middle man and just bury it directly?

The microplastics which we don't see always comes to my mind when I see plastic reused in ways such as this.

Though it probably does depend on the type of plastic, but I'm no chemist.

This is plastic that would go to landfill. Expect it to contain just about everything.

I don't expect this to be heavily processed. More like melted together with some additions.

Microplastics is a huge problem, BUT I can't imagine this being worse than things like tiers and shoe soles.

> if you just compress the plastic into a block and lay it down to make a path then as it deteriorates surly you are just contaminating your environment with mico-plastic particles

The article says that the plastic is mixed with sand, heated, and then compressed into bricks. Given this, is your comment still valid? Honest question, I'm not a material science person.

Yes, the plastic in this case acts as a binder, in fact it would potentially be worse since the heating likely evaporated or decomposed most of the plasticizer which would make the plastic more brittle and more likely to wear off into micro plastics.

Someone mentioned that the pavers are made from plastic bottles that already deteriorate and shed microplastics into the environment. At least in dense brick form the surface area is dramatically reduced and the deterioration rate slowed.

The alternative is to throw all of this plastic into a landfill where it will… leach into the soil and contaminate the environment with plastic particles. At least this option stabilizes the plastic for a period of time.

I would have thought dumping the plastic in a deep pit, perhaps with some kind of solid lining would slow/prevent the plastics breaking down into "micro particles" (whatever they are) and ending up in our food.

Ironically most proper landfills (at least in the first world) use plastic liners along with clay as part of their barriers to prevent water contamination from other trash. I am no expert - so I cannot say if the barriers put plastic in the groundwater but that method prevents more acute toxins like dioxins and oil from getting in.

Not a structural engineer, but I thought that the beams are the load bearers, while the bricks are more of less just filling vertical space.

I think another interesting point to consider is cost. I watched a video a while back about a premise of using plastics for building roads, and in addition to the deformation/UV deterioration issues being brought up, another issue that was brought up was that concrete is cheaper than even the lowest quality recycled plastic.

> the load bearers, while the bricks are more of less just filling vertical space

Bricks are decorative in a few buildings, but this is by far the minority.

Where bricks are used in < 8 floor high buildings, they normally are supporting the weight of the entire structure.

Where do you live that a building of modern construction is supported by bricks? In the US, multi-story residences are built on wood with a brick facade. Multi-story commercial buildings are built using wood up to 4 stories (depending on locale), and steel after that.

I live in Poland. Almost all buildings outside cities are bricks with bricks being load-bearing.

In cities, almost all buildings older than 1950 are also made from bricks.

The US is the odd one out... I completely see why you'd make a temporary building out of wood so that you can build it in just a few days.

But if this is a house, expected to last 150 years plus, and you're already bringing lots of bricks to the site, you really ought to be using the bricks to hold the building up and reserving the wood for the internal floors and other things that will be replaced every 75 years.

A bit off topic but wood houses can, if done right, last quite a lot longer than 150 years.

The oldest timber frame house in the US dates to 1637.

Wood easily lasts 200+ years as long as it’s thick and dry. It tends to sag over time, but most buildings end up being fairly temporary on those timescales.

You can build wooden house that would stand 100+ years. Not US-style houses from planks, though, you just cut trees and use their trunks as a whole to build walls. Also you should protect it from the rotting.

There are a very large number of 100+ year old wooden homes in the eastern half of the US. Check out Zillow with the "year built" filter. Even if you set the filter to limit results to 1899 and older, the vast majority of homes are of wood construction.

Heck, I live in a 91 year old wood framed and clad home in California - this isn’t limited to the east coast.

This house is going to outlive me as well, barring a natural disaster (which it is better suited to withstand than a masonry home, given that my most likely disaster is an earthquake).

We don't use bricks for structure any more because earthquakes. Wood buildings fare much better when shaken. We also have plenty of wooden houses that have stood for 150 years.

Bricks are not nearly as strong as you intuitively think. They do great in compression, but terrible in tension. Bricks are also terrible insulation. Real structural engineers take this into account, and thus often use wood or steel (or other materials) depending on what really matters. And of course the entire structure needs to be designed as a whole.

Unreinforced masonry is weak in tension because of the weak binding interface between the masonry unit and the mortar. The reason masonry is used in wall construction and not in, say, a suspended floor, is precisely because walls don't typically experience tensile forces. Any tensile force resulting from e.g.: wind loading on the entire structure is typically overcome by the self-weight of the masonry.

If there is a special case where tensile forces are expected, for example a retaining wall, or a mid-rise structure, or earthquake load, the engineer will specify the the masonry is reinforced with steel and then it can resist tension through the unit/mortar interface just fine.

It is a poor structural engineer who tells the architect masonry isn't an option because tension.

The tension is resisted via the steel, not the CMU/mortar interface. Masonry behaves similar to concrete (that’s what the C in CMU stands for...) and suffers from the same issue as concrete re: lack of tensile strength. It is not the mortar interface which makes masonry a problem for tensile loading conditions but the structure of the masonry and mortar itself. They simply are not amenable to carrying tensile load at a microscopic level.

I don’t know what structural engineering you’ve done or what jurisdiction it’s in, but for practical purposes on the west coast in America, structural masonry isn’t an option beyond maybe 3 stories because of tension (due to seismic demand) and any structural engineer that says otherwise is looking to get sued for negligence.

Elsewhere in America this is less true but still most modern engineering doctrines would lead you quickly away from masonry for anything substantial, although cost and schedule is obviously a key factor in masonry’s favor.

Everything else about the use of masonry in walls I generally agree with, although the move away from allowable stress has impacted it as described above. Except maybe I would quibble about the use for retaining walls. CMU can be particularly cost effective for some geometries of retaining walls when used with steel.

Wood lasts 150 years plus. There are environmental factors that, unmitigated, can damage wood. But the same is also the case for masonry construction. They both have their pros and cons. And now that things like vinyl siding exist, wood homes can last a long time even with minimal maintenance.

Wood houses can last just as long if they are properly built and maintained. I will grant you that many buildings in the US aren't built or maintained to last that long, but they can and do exist and it is what most builders would prefer to build if there was the demand. Wood is also much easier to repair if there is damage, or easily jacked up if the foundation moves over 100 years.

Just FYI, Hōryū-ji is a temple built of wood that has lasted 400 to 1300 years (parts have been repaired over the centuries). It's all about how you care for the building.

https://en.wikipedia.org/wiki/H%C5%8Dry%C5%AB-ji

Central Europe mostly builds from bricks. Not just classical red bricks, Ytong is a very popular type too.

Wooden structures copied from Scandinavia are slowly coming into fashion for smaller family houses (the construction process is very fast compared to bricks), but they are still very much in minority.

Taller constructions are concrete + steel.

> Taller constructions are concrete + steel.

There have been some advancements in wood for taller structures in recent years. Basically they have come up with wood that is as strong as concrete.

Main problem is fire/pests/rot/etc so you can't build crazy big but there are now 7 or 8 story tall apartment buildings made out of wood mainly in Helsinki for example.

Making apartment buildings out of wood is also much more environment friendly then concrete (somewhere around 50% less total co2)

Fennoscandinavians are very good with their wood. (Pun not intended.) When other nations try to imitate their know-how, the result is usually subpar.

Structural wood can be more fireproof than steel.

I saw this in an excellent exhibit at the National Building Museum in DC a couple of years back. Will try to track down a reference.

Some discussion (and dead links) near the bottom of this thread - https://news.ycombinator.com/item?id=16331375

In Israel almost all construction, even single family homes (not that there are many of them), has concrete/steel beams and floors as the load baring infrastructure, and light Ytong bricks serving mainly for insulation. But it's super common to remove brick walls, interior or exterior, to make changes to home layouts, and as long as you don't touch the beams it's safe.

While sibling comments mentioned a bit about differences in building approach with heavy use of brick and concrete in Europe, at times it reaches into cultural incomprehension.

When US action movies started to show up more in Poland, many people joked how american movies exaggerate things by using cheap plywood scene sets for houses. Finding out that american homes are actually built like that was a bit of a shock to many.

To be fair, a little 4.9 earthquake counts as one of the biggest ever recorded in Poland.

And if you know anything about electrical wiring, do not look up how they do it in those plywood houses in US, any European building inspector would have a heart attack :)

I get shivers just from the standard outlets in USA...

What's wrong with our outlets? We've got less voltage, and a ground plug that makes contact first. When the outlet is in a room with water, or outdoors, it goes through a ground fault interrupter to keep people from being electrocuted.

We reserve 220 volt outlets and higher voltages (3 phase 480, etc) for the larger loads, and those plugs are huge, and not something found in a typical home.

While this is all true, less voltage comes with a price and that is more current.

2 times less voltage === 4 times more heating for the same resistance (heating is calculated from R times I^2).

This means that short circuits, wiring problems are potentially much dangerous.

I live in a building where bricks are very much load-bearing.

I have also lived in buildings that had steel or wood beams in walls for the purpose of keeping the wall rigid (so that it doesn't buckle), but the bricks were still holding most of the load.

First-world vs third-world (approximately).

In the first world, brick construction is extremely expensive and you're right -- modern residences are often built with structural beams (whether wood or steel), and the brick is usually just a veneer.

But in the third world, variants of brick (e.g. cinder block) are often the norm, and are structurally load-bearing, and work fine for two to three stories. And they're very easy and cheap to build with.

The US has a ton of cheap lumber so load-bearing wood frames are common. Many countries don't have forests like that so bricks/blocks are the way to go.

Cinder block construction can also be difficult to insulate and hide services such as electricity and plumbing behind. In addition, brick buildings are a bad idea in areas subject to [seismic events](https://www.npr.org/2010/01/14/122547242/haitis-buildings-we...).

I was under the impression they used metal to reinforce masonry, but apparently not all everyone does. Found an article that goes into more details and lists pros and cons of the masonry approach here:

https://theconstructor.org/construction/masonry/load-bearing...

I have to disagree, and I don't think the first world vs. third world comparison is helpful.

Bricks are quite common in Europe, at least for buildings up to a certain height. The resulting buildings here (in Germany) offer higher living quality with better thermal and acoustic insulation than a typical North American beams + drywalls building. That's just an observation though and maybe the general construction method is not the cause - maybe it's just because our windows and doors are much more solid.

Yeah, it’s not a 1st / 3rd world thing as much as a regional thing. Here in California wood is practically free, while stick and sheathing construction is the best way to build an earthquake resistant home. Other parts of the world have different concerns and costs.

Similarly, it's not common to build stick houses in Florida. Definitely regional.

Bricks and stone provide abysmal thermal insulation. North American drywall with insulation is far, far better thermally. It's not even close.

Also... what does "much more solid" windows mean exactly? Like, are you saying European window glass is... thicker or something? Which wouldn't make any sense, and I'm not even sure what a benefit would be?

Tilt and turn windows, with triple or quadruple panes, low-E glass, and two gaskets for air sealing are much more common in Europe than in the US for residential construction, where they would only be seen in highly energy efficient high end construction.

They're also only seen in high end energy efficient construction in France, Spain, the Netherlands and I've never seen them in Eastern Europe. They're frickin' expensive! They may be more common than in the US, but still not "common".

Maybe triple-glazing is more rare, but at least in Poland, by my observation, almost everyone seems to have double-glazed, PVC-framed windows. I only ever see single-pane windows in really old and poor houses. IIRC, there was a rush of replacing old windows with double-glazed ones in the late 1990s/early 2000s.

Indeed. And double-paned windows are in the majority of homes in the US [1]. And triple-paned windows are a lot more expensive for not a ton more benefit no matter where you live.

Unless someone has some actual comparative statistics, the idea that European windows are somehow more "solid" than North American ones isn't at all obvious. I've spent years living on both continents and never noticed a huge difference. What matters the most is simply the age of and investment in the building, not which continent you're on.

[1] https://www.dwmmag.com/survey-multi-pane-windows-now-on-59-p...

> Bricks and stone provide abysmal thermal insulation

Even 80-90 years ago, brick housing in wester Europe was made with walls of two layers with an air/insulation cavity inbetween. Current practices usually don't use clay bricks but aerated concrete [1] which has great thermal insulation, plus insulation layers on top.

> what does "much more solid" windows mean exactly

Triple-glazed windows with well-insulated frames, rather than single-pane push-up windows that leak heat like a sieve. Massive difference in thermal and acoustic insulation.

[1] https://en.wikipedia.org/wiki/Autoclaved_aerated_concrete

I was curious as to the cost of bricks so I did a bit of research...

A standard two-cell "cinder block" in the US weighs around 17.5kg and costs around $2.00 at home depot [1]. I suspect they'll be much cheaper in bulk. Maybe $1.50 if you buy thousands?

The same thing costs ₹65 INR in India [2]. Or about $0.89 (₹73 INR = $1 USD). Not sure if they would accept orders for a single block at that site.

So, more expensive in the US. But not extremely so.

[1] https://www.homedepot.com/p/16-in-x-8-in-x-8-in-Normal-Weigh... [2] https://www.indiamart.com/proddetail/concrete-hollow-blocks-...

I guess what is more expensive is to pay the builders in a first-world-nation, since brick-laying is labour-intensive and requires skill.

Stick building homes is labor intensive and requires a skill as well…

Obviously it's the difference between the two.

Bricklaying requires much more labor than wooden frame construction. And it requires more skill which most contractors do not have.

It's more expensive for these basic economic reasons.

Major problem with plastic in roads is thermal stability and abrasion from constant wear. In the end, concrete is not only cheaper, but also much safer option.

Standard design for a UK house uses bricks (and an interior cinder block lining) to bear all loads unless the design calls for a very narrow pillar.

Even where a timber frame bearing roof and floor loads exists so wall bricks just "fill space", they have to be sufficiently performant under compression to support the weight of brick courses above them.

For limited load bearing, aircrete (a concrete foam) is cheaper, and a better insulator. The main issue is that the cure time is much longer.

My father actually ran a plastic waste recycling business similar to this about 20 years ago. He didn’t add any filler to the plastic so it was just ground up and run through an extruded and then injected into moulds. He mostly made beams and boards. The business didn’t survive but we still have a number of the plastic boards and beams. They’ve been in continuous use on his property for the past two decades in various incarnations as fencing, shed walls, sleepers used for keeping material off the ground, etc. They haven’t degraded as far as I can tell although they might be slightly lighter in colour. Only some of the 2x6 boards deformed and broke when they were used as a fence but I think that has more to due with livestock pushing up against them.

These bricks will probably work fine as foot paths, the sand and dye in them will slow UV degradation and foot traffic is unlikely to wear them much. I wouldn’t build a house out of them, offgassing would be a bigger concern for me than sagging, at least on a 1 story structure. A brick is a widely useful thing so I hope her business does well. She’s essentially just making plastic composite which is something you’re seeing in North America now used for decking.

You wouldn’t use plastic bricks for building without either serious fire risks. A non-flammable coating on the brick could potentially be developed, but not easily and perhaps not cost effectively.

This is what happens when you use polyethylene as part of your building: https://www.bbc.com/news/uk-40301289

The bricks contain polyethylene, but a large part, probably most of it, is sand. Also, it is not foam in enclosed spaces, but a full hard material.

A non-flammable coating would perhaps be a layer of plaster or paint?

I think you are seriously overestimating the flammability of the product. Have you seen rooms with vinyl floors, PVC windows, foam / fake leather couches? Each of those will burn more easily a viciously than the bricks.

My concern would be with possible structural failure at high temperatures and some fires may be able to pass through walls of these bricks. However, I don't think they are building apartment buildings from these bricks.

From article: “In his report to the public inquiry, Professor Luke Bisby said evidence ‘strongly supports’ the theory that the polyethylene material in the cladding was the primary cause of the fire's spread.” and “The ACM (aluminium composite material) product on Grenfell Tower incorporates a highly combustible polyethylene polymer filler which melts, drips, and flows at elevated temperature.”.

I am not a materials engineer, but it looks to me that bricks with more than 10% of polyethylene are likely to be flammable in the case of a house fire.

I don’t know whether the Grenfell tower cladding had filler, but it is common for the polyethylene core to be mixed with filler within the cladding to help protect against fire, for example the ALPOLIC A2 product mentioned in [1] has an image showing a table with:

ALPOLIC fr: Combustible ingredients < 30%. < 13 MJ/kg

ALPOLIC A2: Combustible ingredients < 10%. < 3 MJ/kg

And [1] says “Its calorific value is given as something less than 13 MJ/kg, more than four times the value considered to be of ‘limited combustibility’ in the UK”.

Above facts are why I think even a large percentage of sand might still leave flammable bricks (polyethylene is like solid petroleum, until it melts and behaves more like a liquid or wax with a viscosity depending on multiple factors).

[1] http://theriveroflife.com/2018/02/08/grenfell-tower-is-the-c...

PE has a melting point around 100-150c. In house fires, flashover (the point where fires become widespread because hot gasses created by smaller fires self ignite) are in the realm of 3-4x this (~500-600c). Your bricks would literally be loose sand by that point.

You need space shuttle aerogel tiles not paint.

I'm well aware a sustained fire will melt and burn the bricks. The question is how fast and how easy it is to ignite.

Sand has a lot of thermal mass, so with some insulation against surface fires (PE surface is easy to ignite) - say a proper coat of paint, or maybe some plaster - a lone kindling would not ignite the bricks. A proper fire will, but then you should be running away anyhow.

Still, if I were a firefighter, I would not approve of such building materials, unless the shoddy construction is well known, so noone dares go inside, mainly because it's likely to collapse and turn in to a bunch of hot burning goo. Luckily, they seem to use it for pavement.

> a lone kindling would not ignite the bricks

again, far before a fire reaches a point where it's widespread the heat of the gasses created by a small fire are already 4x what these bricks can stand before the binder involves melt.

So long before you're worried about thermal mass, there would be nothing holding these bricks together and you have a mass of loose sand and melted plastic.

You could paint it with intumescent paint but I doubt it would be effective given the low melting temperature, and would probably end up costing as much or more as the brick.

I dare you to take a thick PE panel/plate, paint the surface with regular non-flammable interior paint (enough so you can't see through), and then light it with a match or a cigarette. Preferably in a vertical position through the painted side.

If unconvinced, try the same with a piece of old sofa, fake leather or vinyl flooring (with or without paint).

I actually studied fire engineering, so rather than a dare, I've actually burned loaded concrete/steel beams, and connections in giant furnaces that get a lot hotter than your match to evaluate their fire performance.

I don't think you're listening to what I'm saying about the common air temperature around small fires (auto-ignition of hot gasses at ~600°C is common) and the melting temperature of the binder in these bricks (150°C max).

It's not about ignition of the PE, its about cohesion of the brick PE binder (and thus the sand) at higher temperatures. Your painting this brick that will lose cohesion will do exactly nothing for the performance of the brick.

I dare you to think about it critically, instead of making useless dares that don't address what the other person is saying.

So you're saying the bricks that are close enough to an actual (not teensy) fire will melt/spill/spread? Why is that such a big deal?

I mean, yes, it's nowhere near western building codes, and if there is a non-trivial fire, you need to get out, fast. Much faster than with most typical building materials, though the bricks won't come loose instantly, and that has to do with thermal mass, conductivity, temperature and amount of heat.

Note, a match will not do, if painted. A blast furnace will, but I do not see the relevance.

Yes, I may have overestimated how much fire the bricks might survive, in my first comment, but I'm not saying the building would withstand a fire - the main point is, that it's more resistant than EPS cladding, couches and PVC flooring, so not as dangerous as it might seem.

Their website mentions "Ideally most suitable for parking areas not commonly frequented by heavy trucks" on their heaviest duty brick. So they seem to be aware. They only reference use as pavers.

https://gjenge.co.ke/our-products/

Fun fact: most unrecycled plastic waste (majority of plastic) from ends up in one of the two places: landfills or the oceans. It is already breaking down and leaching into the environment. I see this as an absolute win unless we stop using plastics altogether.

> Just because the brick is able to withstand throwing it on the rocks doesn't mean it is not going to deform under load.

The end of the article says they founded in 2017 and have recycled 20 tons of waste. Maybe structural issues will emerge after 5+ years of use but it sounds like this approach has already had a fair amount of real-world usage.

20 tons - enough to build what, 1-10 houses over 3 years? - doesn't sound like it's been tested at scale to me.

I'm still confused why there is so much discussion in the comments around using these bricks in buildings. The video is pretty clear about them being used as pavers.

Most likely not - stuff will just fall down and nobody will talk about it. I'm sure the bricks they made in 2017 that actually see any load are already seriously deformed from creep/cold flow.

> Brick strength is measured in ability to withstand deformation under load and as far as I know there isn't any popular "plastic" that can do comparably.

By definition something plastic will deform, else it wouldn't be plastic! A "rigid plastic" would be like a "miniature giant"

The plasticity in their name refers to the plasticity during manufacturing which means they can be easily shaped or molded.

In their usable form plastics have varying modes of failure depending on their material properties, many of them do not deform at all under stress but rather shatter just like glass.

In this case the world "plastic" is used in its popular sense.

Vast majority of "plastics" are plastic in physical sense. But some are not. Some undergo physical or chemical change after they are cooled and are on longer plastic in the physical sense.

So maybe not "by definition".

I like these kind of stories. Recycling or waste management infrastructure in many countries doesn’t cope well with plastic waste. And many countries that do a good job of collection send bales back to Asia in return trip shipping containers where much of it ultimately ends up fueling coal power stations or the fate described below.

Bricks with plastic binder aren’t perfect; leachate and durability under load and abrasion are issues to be aware of.

But the alternative and predominant plastic disposal method in this and similar contexts is dumping in a ditch, in a field or in an unsealed ad hoc landfill at best, or more probably burning in a heap with whatever fallen leaves and other garbage there is that’s remotely flammable. Which results in a toxic chemical smog that persistently contaminates the air, soil and water.

She's a materials scientist. I'd wager that she's considered all of these factors. She's also been doing this for a while, and produced tonnes (literally) of these for, if I read correctly, a year and a half. Maybe consider that she's thought through this?

Of course she has. In fact she indirectly confirms that the common misconceptions regurgitated about plastic do not apply here. She takes the plastic that cannot be recycled using typical methods. The reason why some types of plastic cannot be recycled is because they cannot be melted. This is true of all thermoset plastics, and it is practically true of some thermoplastics as well (at least after they have been repurposed a couple times). The only way they could be softened enough to bind with sand is by softening them in an environment with high enough pressure and temperature, but devoid of oxygen (otherwise they'd just burn).

And even if they were using melty thermoplastics, the properties will still change drastically the moment you introduce a substrate like sand or gravel and turn it into a composite. Just like how there is a massive difference between pure Portland cement (extremely brittle, with almost no load-bearing capability) and concrete, which is a composite. Nobody seems to regurgitate these rubbish misconceptions about plastic when talking about carbon fiber composites (which are held together by plastic!).

I don't think I'll ever understand the techie's tendency to think they know more about certain fields than specialists that work in those fields.

Based on the shape and the pricing per square metre, it looks like the primary use case is for pavement.

As for being a "horrible idea", this is what happens to plastic today in the slums of Nairobi:

https://media.gettyimages.com/photos/kibera-slum-nairobi-pic...

Even if the bricks leach a bit, it's still much better than the status quo of soaking individual plastic bags in sewage for years.

The plastic acts like a rebar, allowing the brick to absorb and mitigate fractures that would ordinarily crack the brick and compromise it's integrity. They would not have the same compressive strength as a cement brick, but would likely fare far better for use cases like pavers and retaining walls. I would imagine they perform better in earthquake situations and may have longer longevity than steel rebar enforced concrete.

These bricks could fill a portion of space within another substance - concrete? to reduce the amount of the latter required.

> Also, plastics tend to get soft rapidly at temperatures. I don't think plastic bricks exposed to sun (Kenya?) would fare for long.

Yeah, it can get hot in parts of Kenya. But this is in Nairobi, which is somewhat elevated, and doesn't get too hot at all.

There are plenty of uses of bricks that do not need to support the weight of a multi-story buildings. Just because an item doesn't fit for a particular use does not mean it is not a viable solution for other things. Paving stones, mailboxes, retaining walls, etc are all examples.

I for one can appreciate that someone is taking effort to resuse/recycle plastic trash into something useful like this. Maybe rather than shitting all over something for a use it's not necessarily intended for, maybe try to think of other uses this kind of innovative processing can be improved would be much more productive.

Of course there are uses. I am even very happy people try to re-use what would normally be put to waste (unless it causes more plastic to disperse in environment).

Just don't claim it is "stronger" than regular brick if that is not true.

> Maybe rather than shitting all over something for a use it's not necessarily intended for, maybe try to think of other uses this kind of innovative processing can be improved would be much more productive.

Not a very constructive response. Do you have any counterpoints to the other user's points, or do you just not allow people to point out potential issues with materials that may be used for human housing? Progress requires a balance between some people focusing on achievements and some pointing out the things that can still be improved. If I were going to rely on a new material, I'd definitely want its issues to be pointed out and addressed first, rather than just jump to using it.

There is a little thing called tone. And criticizing someone’s over negativity is constructive.

You’d want that negativity problem to point pointed out and addressed, wouldn’t you?

I wouldn't. I would rather a world where people are strong enough to deal with "tone", which seems to be a highly subjective thing. How about giving someone else the benefit of the doubt instead of pointing out "negativity"?

The original article says nothing about the plastic bricks being used for housing. All the HN criticism about them not being usable for housing is attacking a strawman.

The title of the post is that these are stronger than concrete. The title isn't "these bricks could be used for many things". OP is directly responding to a dubious claim. Where as you would seem to prefer they ignore the dubious claim and just be endlessly positive.

I'd sure as hell rather know if my home is going to collapse if I build them out of plastic bricks than someone telling me all of the things I could have used them for instead.

OP did not directly respond to the dubious claim but you did. Thank you for reminding me that they're claiming this is stronger than concrete. That indeed is dubious. I think the conversation is swinging too far in the opposite direction, however, and many people seem to be writing this off.

Reply on news.ycombinator.com