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Cake day: March 31st, 2025

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  • 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.

    The Calcium Carbonate degrades into Calcium Oxide

    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




  • coated rebar isn’t, it’ll always get dinged somewhere. stainless is expensive and the real available scalable option is either galvanized or sometimes basalt fiber, or glass fiber but i’ve not heard about it too much. the most important factor in slowing down corrosion is how thick concrete layer is on top of rebar, because concrete is very slightly porous and will let oxygen in, but the thicker that layer is, the slower oxygen gets to rebar, then the slower corrosion is, and this means it takes longer for rust layer to grow enough for concrete around rebar to fail due to swelling, because rust takes more volume than corroding steel

    a bit of vinegar might strip zinc layer, but won’t do too much and definitely it won’t matter long term until most of zinc layer is gone. salt also promotes corrosion but this also depends on oxygen availability and won’t be too fast, it would only matter if there’s salt in concrete in large amounts