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In a First, America Dropped 30,000-Pound Bunker-Busters—But Iran’s Concrete May Be Unbreakable, Scientists Say (www.popularmechanics.com)

submitted 5 days ago by [email protected] to c/[email protected]

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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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[–] [email protected] 222 points 5 days 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] 42 points 5 days ago* (last edited 5 days 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] 11 points 4 days 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.

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[–] [email protected] 60 points 5 days ago (2 children)

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

[–] [email protected] 12 points 4 days ago* (last edited 4 days ago) (2 children)

That's impossible. "Make America Great Again" is a slogan that he can only abuse as long as there are problems. If he wants to stay in power it's in his best interest to create problems. It's what fascists dictators have been doing since forever. Even if there are no problems they will point towards something and make you think it is a problem, so they can market themselves as the solution. If he would "win" he would lose his power, which is obviously the opposite of what somebody like Trump wants.

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[–] [email protected] 68 points 5 days ago (1 children)

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

[–] [email protected] 27 points 5 days ago (1 children)

tactical

Lol, they're gonna do the strategic one next

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

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

[–] [email protected] 20 points 5 days ago (4 children)

Strategic = Hiroshima getting obliterated

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

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[–] [email protected] 13 points 4 days ago* (last edited 4 days 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] 6 points 4 days ago

In common usage they're equivalent to small and big. In practical terms, all nukes are strategic - use of a nuke has profound global diplomatic repercussions.

[–] [email protected] 9 points 5 days ago (2 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.

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[–] [email protected] 48 points 5 days ago (4 children)

Giving the yield strength in psi is the most pointless thing ever. Every single engineer would use metric Pa so its clearly a conversion for the average american idiot but the average American idiot has no idea what yield strength is.

[–] [email protected] 21 points 5 days ago

We dropped a big boom worth 120000 hamburgers and the explosion was many football fields big. Salute to the brave troops.

[–] [email protected] 21 points 5 days ago* (last edited 5 days ago)

Your comment is informative but now all I can hear in my head is Green Day’s “American Idiot”.

[–] [email protected] 10 points 5 days ago (1 children)

Sorry bud, you're straight up wrong. Aerospace and defense in the US very much still uses the inch-pound-second system of units.

I'm not a concrete guy, but I know that metals and composites have material properties certified for use in civil and commercial aviation are given in psi in MMPDS and CMH-17. I would be willing to bet that concrete specifications in the US are no different.

I could keep going. Our bolts are specified in ultimate tensile strength by psi. Structural steel standards use minimum yield strengths in psi. There is literally a type of steel called A36 because its minimum required yield strength is 36,000 psi.

[–] Hawk 7 points 5 days ago

Yeah psi is a pretty common unit and trivial to swap between if SI is needed.

Arguments like above often show a lack of real world experience.

[–] [email protected] 7 points 5 days ago* (last edited 5 days ago)

I prefer my mechanical stress calculations in millidynes per square kiloparsec thank you very much.

[–] [email protected] 18 points 4 days ago

"no, these missiles only bust the bunkers we tested them on."

[–] [email protected] 40 points 5 days 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] 12 points 4 days 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] 39 points 5 days ago (6 children)

Nothing is unbreakable.

[–] [email protected] 18 points 5 days ago (12 children)

And no bomb is irresistible.

[–] [email protected] 9 points 5 days ago (4 children)

That's why we need the Orbital Ion Cannon.

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[–] [email protected] 13 points 5 days ago

Except copeium.

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[–] [email protected] 34 points 5 days ago (6 children)

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

[–] [email protected] 23 points 5 days 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] 28 points 5 days ago* (last edited 5 days 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...

[–] [email protected] 13 points 5 days ago

They can try one more time but worse

[–] [email protected] 12 points 5 days ago (3 children)

I mean they usually only do about 30 damage anyways.

Source

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[–] [email protected] 9 points 5 days ago (2 children)

The article is 3 years old

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[–] [email protected] 24 points 5 days ago* (last edited 5 days ago) (3 children)

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

[–] [email protected] 12 points 5 days ago (4 children)

Hardly. Did you read the article?

[–] [email protected] 21 points 5 days ago (1 children)

The greater strength is achieved by turning concrete into a composite material with the addition of steel or other fibers.

Fiber reinforcment is thousands of years old.

[–] [email protected] 17 points 5 days ago (1 children)

Calling that pyramid age I think is a little disingenuous, they didn’t have 40,000 psi concrete back in those days.

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[–] [email protected] 11 points 5 days ago* (last edited 5 days ago) (1 children)

So I did not read the article because of a paywall I'm too lazy to circumvent right now

But from OP's summary, the main technology they're talking about is concrete reinforced with steel or other fibers.

And that's definitely more advanced than "pyramid age"

But it's also pretty much a direct descendant of mud brick reinforced with straw which humanity has been using since well before the pyramids. Same basic concept, different materials.

So yes and no.

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[–] [email protected] 21 points 5 days ago

Impressive.

[–] [email protected] 9 points 5 days ago (6 children)

They mean mixing in steel dust or nylon hair?

Hard to believe this is a recent enough thought.

[–] [email protected] 20 points 5 days ago (2 children)

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

[–] [email protected] 6 points 4 days ago (6 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] 7 points 4 days 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.