this post was submitted on 17 Jul 2026
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The concrete is actually highly acidic but the outer layer cures to become alkaline and the two layers together end up becoming water resistant, so by adding acid to the surface it can lose its water repellent capability and weaken faster.
If the concrete were sealed with a wax or an acrylic then Acetone would also be effective.
concrete is calcium carbonate and silicate, both are basic. it's also slightly porous but mostly waterproof by itself, doesn't matter that hard in this application since there will be AC removing water from the inside 24/7 anyway
Carbonation causes acidity and the traditional methods of creating concrete involves furnaces which introduce various forms of carbonation. The Calcium Carbonate once dissolved in water will start to form the Calcium Hydroxide layer on the surface, thats the alkaline layer, and deeper in the carbonation creates acidity.
calcium carbonate is still basic and even hydrogen carbonate is basic enough to be protective against steel corrosion
100% wrong, how come there's more carbon dioxide inside than outside, you're starting from calcium hydroxide and silicate. on the surface there's some carbonate formation from carbon dioxide, but when it can't get there calcium silicate forms instead. either way both are basic
Well, now you're contradicting yourself from earlier when you stated we were discussing Calcium Carbonate and Silicate.
The Calcium Carbonate degrades into Calcium Oxide. Calcium Oxide will form Calcium Hydroxide on the cured surface.
The only reliable way to seperate the Calcium from the oxidation afaik would be the introduction of Chlorine, so you're definitely not seeing the reverse happening regardless of how much carbon dioxide there is.
you see, you can be as wrong as you want to be. i won't be teaching you middle school level chemistry against your will in a comment section. in concrete Ca2+ remains Ca2+, be it as hydroxide or carbonate or silicate and it cannot become reduced in normal concrete conditions and definitely it can't be oxidized.
no it fucking doesn't, this is what happens when cement is prepared in a kiln. near surface of curing concrete calcium hydroxide captures carbon dioxide from air, then this crust of precipitate blocks it from moving deeper. which is why the rest of calcium hydroxide reacts with silica forming calcium silicate, which takes more time and is responsible for late strengthening. before you lost plot i was talking about oxidation of steel rebar, and it depends on many things, but for regular carbon steel if there's no oxygen then it's much slower. and because concrete is not very permeable to oxygen, there are all these engineering requirements about how deep rebar has to be. anyway, a little bit of vinegar would be just neutralized by calcium hydroxide from concrete and won't do anything, a little bit of salt would be diluted massively and also won't do anything, hydrogen peroxide would decompose because anything will do that
You can make it happen faster in a furnace but it will happen regardless.
Oh really? I honestly never considered that possibility and always thought of concrete as a kind of inert “stone,” I find this legitimately interesting.
My understanding is that the genius of such attacks is they don't actually have to do the damage but if there's the fear of chemical damage you don't want to build the rest of a building on top of it.
This right here is the answer. The possibility that the concrete cure was all or partially disrupted can mean the concrete has to go away and be re-poured.
That would be a great reason to announce the damage as well, which they did.
Check out the Hoover Dam. It's concrete is still curing to this day!
Stone itself isn't inert either?