this post was submitted on 25 Jun 2025
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Previously, a yield strength of 5,000 pounds per square inch (psi) was enough for concrete to be rated as “high strength,” with the best going up to 10,000 psi. The new UHPC can withstand 40,000 psi or more.

The greater strength is achieved by turning concrete into a composite material with the addition of steel or other fibers. These fibers hold the concrete together and prevent cracks from spreading throughout it, negating the brittleness. “Instead of getting a few large cracks in a concrete panel, you get lots of smaller cracks,” says Barnett. “The fibers give it more fracture energy.”

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[–] skisnow 32 points 6 hours ago (1 children)

I suspect the world would be safer if everyone just let Trump think he won.

[–] [email protected] 1 points 1 hour ago

I wonder if Hasbara accounts are pressing this narrative?

[–] [email protected] 5 points 5 hours ago (2 children)

They mean mixing in steel dust or nylon hair?

Hard to believe this is a recent enough thought.

[–] [email protected] 4 points 3 hours ago (1 children)

It's been done in mining for decades

[–] [email protected] 3 points 3 hours ago (1 children)

I asked because I've heard such advice for bloody countryside home floors. Not even something requiring it.

[–] [email protected] 4 points 2 hours ago

Turns out that anti-cracking tech is widely applicable, if a bit expensive.

[–] [email protected] 9 points 5 hours ago (1 children)

I doubt it's a recent thought, knowing civil engineers, they're absolute perverts when it comes to concrete.

[–] [email protected] 3 points 4 hours ago (2 children)

IIRC this type of thing isn't new - there was research into the possibility of making ships out of ice mixed with sawdust in WWII.

[–] [email protected] 2 points 43 minutes ago

It also wasn’t and isn’t that crazy of an idea.

It’s strong AF, buoyant, and you can repair it at sea using the ocean around you.

You just need a reliable way to keep it cool.

[–] [email protected] 2 points 2 hours ago* (last edited 2 hours ago) (1 children)

How is the fleet holding up?

We almost made it this time!

Oh well, let's freeze another fleet, wait for January and try again

[–] [email protected] 2 points 42 minutes ago

Look up pykrete, it’s actually a really cool material

[–] [email protected] 61 points 12 hours ago (1 children)

Sounds to me like someone is trying to justify actually using a tactical, atomic bunker buster.

[–] [email protected] 24 points 12 hours ago (1 children)

tactical

Lol, they're gonna do the strategic one next

[–] [email protected] 5 points 7 hours ago (5 children)

I never really got why tactical and strategic nukes are so wildly different. Aren't those words more or less synonyms?

[–] [email protected] 5 points 1 hour ago* (last edited 1 hour ago)

The reality is that "tactical" and "strategic" are functionally meaningless adjectives when applied to weapons or systems.

Theoretically, "tactical" refers to how a military unit engages another military unit. It is how a commander wins a battle against an enemy unit.

"Strategic" refers to how a nation engages another nation. It is how a government wins a war.

The term "tactical nuke" referred to something that a lower level commander could have been authorized to use under his own judgment. If Soviet tanks were rolling across Europe during the cold war, commanders may have been granted the discretion to use small nuclear weapons to halt their advance.

Since the the doctrine of Mutually Assured Destruction was established, there has been no such thing as a "tactical" nuke. Any wartime use of a nuclear weapon of any kind demands an escalation to total annihilation. I used the term "tactical" ironically, to refer to a pre-"MAD" doctrine that can no longer exist.

In declaring that conventional bombs cannot penetrate this fixed bunker, it seems that someone is pushing for unconventional warfare. The reality is that this bunker is not impenetrable. It shares the same weakness as any bunker: getting into and out of it. Bomb the entrances to the bunker, and it will take months or years to tunnel back in. Whatever they are doing inside it, they won't be doing until they manage to dig it up again.

[–] [email protected] 5 points 4 hours ago (1 children)

It is like a rifle vs. a cannon.

Yes it is functionally the same, but the "bullet" is much much larger.

[–] [email protected] 1 points 31 minutes ago

Not really. More like a cannon and an artillery aimed at industrial capacity.

[–] [email protected] 18 points 7 hours ago (1 children)

Strategic = Hiroshima getting obliterated

Tactical = The Imperial Palace is obliterated, but rest of Tokyo is mostly intact.

[–] [email protected] 4 points 3 hours ago

rest of Tokio is mostly intact

and housing becomes much more accessible too when buildings are intact but their inhabitants have much shorter lives because of radiation

[–] [email protected] 7 points 7 hours ago (1 children)

Very much not.

Tactical means immediately useful. E.g. use against troops. Strategical means mediately useful. E.g. use against infrastructure and production capacity. Also massively killing civilians. This is where most heinous war crimes live.

[–] [email protected] 2 points 41 minutes ago* (last edited 40 minutes ago) (1 children)
[–] [email protected] 1 points 36 minutes ago

One means directly, one means by middle man. E.g. a president is elected mediatly by electing a law giving council that then votes on who becomes president. As opposed to the people electing said president directly.

[–] [email protected] 5 points 7 hours ago

Generally yield and intention difference, strategic takes out cities, tactical takes out factories, military bases and compounds.

[–] [email protected] 181 points 16 hours ago (6 children)

Holy nothing burger, Batman!

First off, this article is from 2022, re-released to farm clicks from the current hype cycle.

Secondly, this is conjecture on top of conjecture. They discuss that we can't know the current damage from satellite, and Iran down plays the damage. Then they go on to say "concrete is strong and can be stronger".

Articles like this annoy me. It's all based on lots of unsubstantiated claims, and then one guy's theoretical research. We don't know the strength of the bombs. We don't know the strength of Iran's bunkers. We don't know how much damage was done. None of this has changed. I doubt we'll ever really know. But throw whatever political spin on it you want, and now you've got a click worthy news article.

[–] [email protected] 38 points 15 hours ago* (last edited 15 hours ago) (2 children)

There's also the fact that the majority of Iran's nuclear facilities were built before UHPC, the concrete discussed in the article, was available!

[–] [email protected] 7 points 4 hours ago

In the late 2000s, for instance, rumors circulated about a bunker in Iran struck by a bunker-buster bomb. The bomb had failed to penetrate—and remained embedded in—the surface of the bunker, presumably until the occupants called in a bomb-disposal team. Rather than smashing through the concrete, the bomb had been unexpectedly stopped dead. The reason was not hard to guess: Iran was a leader in the new technology of Ultra High Performance Concrete, or UHPC, and its latest concrete advancements were evidently too much for standard bunker busters.

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

Construction on the facility started in 2006, but the existence of the enrichment plant was only disclosed to the International Atomic Energy Agency (IAEA) by Iran on 21 September 2009,[6][7] after the site became known to Western intelligence services. Western officials strongly condemned Iran for not disclosing the site earlier;

Seems to fall into the same timeframe.

[–] [email protected] 8 points 13 hours ago

I was suspicious of that as well, but I'm not knowledgeable enough on that subject to speak on it, so didn't include it. But I doubt any country can build that extensive of a nuclear factory in so few years.

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[–] [email protected] 36 points 13 hours ago (1 children)

That concrete really isn't new and really isn't that special. There's a reason they built it under a mountain - because the mountain does what concrete can't.

[–] [email protected] 8 points 4 hours ago

It is not that it can do what concrete cannot. It is just that digging a tunnel under a mountain is much easier than making a mountain out of concrete.

[–] [email protected] 36 points 16 hours ago (21 children)
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[–] [email protected] 29 points 17 hours ago (9 children)

From this article it sounds very likely that the bunker buster attack failed.

[–] [email protected] 7 points 11 hours ago (1 children)

The article is 3 years old

[–] [email protected] 1 points 6 hours ago (1 children)

But the information still seems valid.

[–] [email protected] 1 points 4 hours ago

It's confirming your bias so you like it...

[–] [email protected] 21 points 16 hours ago (1 children)

And I read that the US used more than half of its stock of these bunker-buster bombs in this attack, the largest conventional bunker-busters in existence. So they can't simply try again.

[–] [email protected] 25 points 16 hours ago* (last edited 16 hours ago) (1 children)

By your math, they absolutely can simply try again: one more time.

By my math, the bunker-buster bomb makers just got a big new contract.

something something DOGE of WAR something...

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[–] [email protected] 21 points 17 hours ago

Impressive.

[–] [email protected] 18 points 16 hours ago* (last edited 16 hours ago) (9 children)

Basically they used pyramid age tech to outplay billions of dollars worth of weapons tech.

[–] [email protected] 2 points 4 hours ago (1 children)

Arguably letting a big weight fall down after being brought into the air somehow is also pyramid age tech.

[–] [email protected] 2 points 3 hours ago

These bombs are not just dead weights. These bunker busters are equipped with precision guidance and fly to and hit a person on the head if they desired. It's also designed to deliver a huge explosion AFTER it penetrates with the kinetic impact.

It can also be set to explode right before impact, like Israel really likes to do when attaching residential high-rises, to deliver maximum destruction and death.

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