Hello all, I am building my first oven and just poured the hearth slab last week. Halfway through the pour I realized I forgot to mix in the lime. I used 15 80lb bags of premix quickcrete concrete. According to Quickcrete engineering, their concrete with withstand up to 300 degrees before breaking back down to a powder form. I guess that's where the hydrated lime comes in, it holds the conc. together. My question is, will the slab get over 300 degrees with about two hours of fire before cooking with 4.5" of fire brick in between? I have received advice from some that say I should tear down and re-pour, to "don't worry about, it would take years for that slab to break down, and it would be just a few bricks settling over time..." I am leaning towards wanting to believe the latter, for the prospect of busting up all my concrete it disheartening. I have reinforced the dickens out of it with rebar and wire mesh. On the other hand, I don't want my oven to cave in on me. Any advice?
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Hearth Slab, no lime...