Hacker News Reader

Comment by iancmceachern | Hacker News Reader

This 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.

View on HN

The 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-plas....

This is where “new car smell” comes from too.

And it's worth noting that this problem that the OP brings up is literally present in every plastic product in our modern world. It's easy to pick apart new ideas with problems that are true for every other existing product. People are like wait, this isn't X, or Y, but it's like neither is the existing status quo, but it is incrementally better in X and Y, so it's going in the right direction, therefore worth doing.

I think the incrementally better argument is missing the idea that we could do something else with the material or fix it before we start using it. By making buildings or roads or whatever out of material that leaches toxic chemicals over time, we are still putting toxic waste everywhere which can slowly have large effects to our environment.

Just imagine being alongside Henry Ford and him making the same argument, "Yeah, gasoline stinks a little but it's definitely better than horse droppings!" Then fast forward to our current global climate problems.

Mixing graphite into HDPE appears to make it immune to UV photo-degradation.

There’s even a company that capitalizes on this by making durable boat hulls with it: https://tidemanboats.com/

Not sure how it holds up in plasphalt, but it could be worth exploring graphite additives.

Exactly. It's called uv stabilization. When spec'ing a resin for a product a designer can choose to go with a UV stabilized resin, which is ok in the sun. Basically they add dirt, titanium oxide, other oxides to the plastic to mechanically block the uv waves.

How does one even begin to address concerns about toxicity with so many different chemicals? Go in order of concentration? Most to least likely to be biologically active based on models? Cluster them and evaluate the clusters?

Slowly make less every year, the goal of rohs, reach, etc. Then work to sequester/store/recycle/breakdown what we've already made in a responsible, economical, and non planet destroying way.

Depending on the stream (source) and chemistries there are ways to separate out plastics of concern (POCs) but they aren’t fully at scale yet depending on stream. It’s also very hard.

You go by separating valuable fractions out first.

They could paint them once installed, like nearly every building on the planet. Simple problem, simple solution.

> 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.

Then get rid of everything plastic you own.

I actually don't have all that much in comparison - packaging is still hard to get rid of, since most of it is non-recyclable.

but, telling others to get rid of plastic while praising plastic (in other comments) doesn't really help the issue that it is a pollutant, flammable, and an overall problem for our environment.

I'm not telling you to get rid of plastic. I'm trying to highlight the hypocrisy of your comment

Just because you think you don't use much plastic in your everyday life, you do. Let's say (god forbid) you go to the hospital or need other health services. Plastic.

Let's say you go to Starbucks amd order a croissant. The croissant is handed to you in a paper bag that to your eyes isn't plastic, but is in fact Coated on the inside with a layer of plastic making the paper not recyclable. That croissant came to that Starbucks in a plastic bag that was thrown away before it was handed to you.

On and on, if you choose to live in our modern world, not as a hermit in the amazon, you are dependent on plastics weather you realize it or not.

> Then get rid of everything plastic you own

followed by:

> I'm not telling you to get rid of plastic. I'm trying to highlight the hypocrisy of your comment

then you give examples of where plastic is. I'm acutely aware of exactly how much plastic I consume, and make a concerted effort to not do so. the Starbucks example? easy to avoid when you don't go to Starbucks. if I want coffee, I can safely either make it myself or take my reusable mug (which, yes, has one of the few plastic items that I care to consume with as a lid) to my local barista. and yes, I know how much plastic went into the production and transport of the beans.

believe it or not, not everyone chooses to go through life with their heads in the sand, but instead try to make a difference. so, before you continue on this line of thought, perhaps you should remember that not everyone in the world are idiots.

some of us (and likely more than you realize) do understand the impact, and make choices to have as small of an impact as possible while realizing exactly how much plastic there is around them (typed on plastic keys).

I'm trying to point out there is plastic consumption where you don't even know, or can't get rid of. In your starbucks example for example. Using a reusable mug and making your own coffee is obvious. What is not obvious is all the plastic and petrochemical derived products used in getting that coffee to your grocery store, or door. It's sent to your grocery, or you, in plastic bags, the mug was fired with natural gas, on and on. You can't avoid it unless you sail to the tropics in your own sailboat, pick the beans, process them into coffee, and sail back.

I'm not trying to pick on you, or your lifestyle, quite the opposite. I'm just trying to point out its not so simple as to say don't use plastics, or all plastics are evil, because they're inherent in our modern life. You couldn't read this comment without plastics. My other comments in this topic talk about reducing our consumption, making more responsible decisions on how we use our resources, all of that is in line with your goals. We just can't be so extreme to say get rid of all plastics, because we're simply all not willing to roll thr technology clock back 50 years across our entire society. It needs to be a gradual weening off, a gradual March toward responsibility.

Should be an ideal to strive towards, truthfully.

agreed, and not a throwaway comment trying to make someone look "smart".

we should all be aware of how much plastic we consume, and work toward consuming less of it, and lower the impact of what plastic we cannot avoid.

Clay and other concrete based bricks must be cheap enough already, and work well.

If we intend to reuse plastic in bricks, maybe use those bricks for building things in and around landfills or things like storing nuclear waste - so that toxicity is concentrated. Otherwise, plastic bricks seem like one of those things that will be discovered to be toxic eventually.

The world is allegedly running out of sand appropriate for use in concrete products. 99% Invisible (podcast) has a episode on the topic I suggest checking out https://99percentinvisible.org/episode/built-on-sand/

Not saying that I want plastic in construction materials or roads though: https://www.theguardian.com/environment/2022/may/19/environm...

The bricks in the story are made of sand, too.

The article you cite indicates that many of these chemicals come from plastic additives. Couldn't these be removed in the process of preparing the plastic,y? The OP indicates they have to select out only the plastics that bind well with the concrete.

Tried to look up "aspirate", but it didn't clarify: https://www.merriam-webster.com/dictionary/aspirate

Note that "twice as much" doesn't mean it's a lot. Nor does the number of chemicals indicate danger.

In this context it means ''to suck in', 'to absorb'

From context, it seemed clear that OP meant the opposite:

That this material would leak out potentially dangerous chemicals.

Article states this is “plastic that otherwise would be dumped in the city’s overflowing garbage heaps.” Environmental impact of these plastics should be weighed relative to the impact of those same plastics sitting in said garbage heaps. It’s likely safer sequestered in a processed brick optimized for durability than it would be rapidly degrading from e.g. thin plastic bag material into microplastics leaching into the soils and water tables around the dump.

The environmental impact of garbage in dumps is extremely low, by spreading these bricks over a much larger area they would probably become a significantly larger environmental issue.

Dumps in operation look disgusting, but long term they end up looking like a regular hill and can avoid contamination of the local water supply etc: https://en.wikipedia.org/wiki/Mount_Trashmore_Park#/media/Fi...

Will wall finishing techniques (water resistant barrier, rain screen & cladding, lime render, drywall, etc) help manage this?

> asphalt, which is just concrete (cement, sand and lime) with some of the cement replaced with oil/tar.

As far as I know, asphalt concrete doesn't contain any portland cement, at least usually. It's just gravel, sand, and bitumen/asphalt/tar.

I think this description of asphalt is in error. Asphalt itself is a form of petroleum, specifically a type of pitch, which occurs in nature and is also known as bitumen. It is used as a binder for various aggregates in asphalt concrete, which is what everyone calls asphalt. I do not think that cement and lime are involved at all.

You're right. He's referring to Asphalt concrete and confusing it with the components of cement. https://en.wikipedia.org/wiki/Asphalt_concrete

> Truly brilliant. It's a new type of composite building material.

[It's been around since at least the 1950's](https://www.sciencedirect.com/science/article/pii/B978184569... ).

in "green" economy you have to MANUFACTURE carbohydrates and then produce plastic from that. no oil, should be default in current thinking.

hydrocarbons XD

Reply on news.ycombinator.com