
Sand scarcity is about more than “running out” of sand - Tomte
https://www.theverge.com/science/2018/9/4/17797394/sand-microscope-grains-scarcity-construction-industry-concrete
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Animats
Making sand by grinding down rocks is routine in the developed and semi-
developed world. The trick was developing a method of rock crushing that
mostly crushes rock against rock, rather than rock against steel. That's the
vertical shaft impact crusher. Wear is much less, the product quality is
better, and power requirements are lower. Lots of videos of this available, if
you like rock crusher videos.

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Cthulhu_
That's something that will probably become more and more commonplace. It's a
few times more expensive (I can imagine) than just digging up existing good
quality sand though.

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kbutler
But it's a more-or-less constant cost (energy costs, maintenance, rock
supply), vs rising costs of sand (diminishing sand reserves, increasing
shipment costs).

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jondiggsit
Things I learned: River sand is the best type of sand to use in Concrete.
There a companies that manufacture sand. Desert sand is too fine to work well
in concrete. There are "sand mafias" in India stealing entire riverbeds of
sand.

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onetimemanytime
_> >Things I learned: River sand is the best type of sand to use in Concrete._

If it's washed and clean of dirt...maybe. But crushed stone IMO is even
better, it's not round and thus performs better in earthquakes.

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jaclaz
>But crushed stone IMO is even better, it's not round and thus performs better
in earthquakes.

Maybe if you manage to pump the concrete with a reasonable wear to the
equipment, you mean.

Normally with crushed sand you need to increase cement quantities (because
more water is needed) and need finer fillers like "flying ashes" and since you
dont' want to have excessive resistance and thus excessive shrinkage, you need
also other chemical additives.

And - just for the record - rounded aggregates tend to make stronger concrete,
not the other way round, not because of the "surface", but because of the
"shape", a concrete made of only spherical (in theory) aggregates has the less
voids, and the more the actual shape of each aggregate tend to be similar to a
sphere the less voids you find in the mix (that need to be filled by smaller
fillers).

Of course this is "generally speaking", concrete is a product not much
different from cooking, you need good ingredients, a good recipe, good
equipment and a good cook to have a valid result.

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Isamu
How to read this headline:

"scarcity" -> "cost"

"is about more than" -> "is about"

"running out" -> "local availability"

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kwhitefoot
Thank you. That saves me the bother of reading the article.

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jachee
The article is functionally a wordier version of "watch the video" anyway.

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mirimir
Yes, there is no article there. I hate that. There's no audio in my VM, for
various reasons, and CC (if even there) is an utter waste of time.

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Tomte
Yes, it's a video. How is that a reason not to submit it? How is your
misconfiguration a reason to complain?

~~~
tjoff
Probably should have a [video]-tag if so. There are also plenty of other
situations where one is unable or where it is cumbersome to be able to listen
to audio.

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oh5nxo
I don't get the reasoning. Unweathered sharp sand has more surface area than
stuff that has been tumbling in water for a long time, no? In my experience
the received wisdom is, that glacial esker sand, sieved, is good for concrete.
Somewhat like the manufactured sand.

But I might very well have misunderstood, or the old folks advice might not be
right. Or it does not scale to industrial uses.

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andybak
And this is why I don't watch videos. 7+ minutes for the same amount of
information I could have skim-read in under a minute.

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blisterpeanuts
get a video speed plug-in for your browser and watch HTML5 videos at 1.5x or
2x. It's changed my life.

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andybak
Tried it. Weird and still slower than reading.

Plus I don't want to pander to the internet's decline into a glorified tv
channel. If they can't write a blog post then to hell with them.

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izzydata
Is it beyond our capabilities to come up with a new composition of concrete
that involves finer grains of sand?

Maybe it is not as strong, but it seems like necessity should involve some
compromises.

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CGamesPlay
I think that's basically plaster of paris? Practical Engineering did a good
demonstration of different concrete ingredients:
[https://www.youtube.com/watch?v=UOHURuAf5iY&vl=en](https://www.youtube.com/watch?v=UOHURuAf5iY&vl=en)

~~~
maxerickson
Plaster of Paris is a different cement than the Portland Cement mostly used in
concrete.

A big difference is that it isn't waterproof.

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_ph_
The information content of the video might be not too big - it boils down that
river sands, which are the best for concrete are somewhat scarce. But it is
worth while watching it, as towards the end they show microscope takes of the
different kinds of sand being talked about. Those takes clearly show nicely
how different the artificial, river and sea sand are with some faszinating
imaginery. So this is a case, where the video adds to the textual information.
Though it takes a while till it gets to the really interesting part.

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lucb1e
I feel like I'm missing out on something here:
[https://snag.gy/hDjiEF.jpg](https://snag.gy/hDjiEF.jpg)

Disabling the ad blocker doesn't work. Anyone else having this?

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sp332
No, in fact for me the text seems to load first and then other elements of the
page load around it. And I'm running HTTPS Everywhere, Privacy Badger, and
Decentraleyes in addition to uBlock Origin (with mostly-stock blocklists), so
if there's going to be an issue I usually hit it :p

Edit: if you click the Readability Mode icon you should at least be able to
read the text. Here is the video:
[https://www.youtube.com/watch?v=V2349cn0-T0](https://www.youtube.com/watch?v=V2349cn0-T0)

~~~
lucb1e
Readability doesn't work for me either, same short piece of text. Checking the
error console, only a warning for some script of LinkedIn that didn't load,
and all the network requests succeeded. Odd. You'd think if it's supposed to
load dynamically (why'd you want to do such a thing anyway? It's not as if the
text is as big as a JS library and they don't mind including those), it would
at least throw an error if something failed.

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mirimir
That's all there is. It's just the lead for the video.

~~~
lucb1e
Oh! Now I get it, thanks.

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csense
I learned in school that silicon is literally the second most common element
on Earth.

So this story sounds like fake news to me.

