I've got a pretty good grasp on chemistry but I'm by no means a concrete expert...
2006-09-11 12:25:36 · 4 answers · asked by Professor 3 in Science & Mathematics ➔ Engineering
I'm wondering about a chunk of concrete that has been a sidewalk or building foundation for 20 years or so.
2006-09-11 12:35:21 · update #1
Yes, it's a chemical rxn because heat is evolved...but water can be separated into its ingredients, yes?
2006-09-11 12:37:15 · update #2
Concrete is like a crystal. It is not just de-hydrated lime but also de-hydrated silica. Mixing in water re-hydrates the material and it binds together. Just like the cupric sulfate crystals they de-hydrate in lap experiments to determine the amount of water due to crystalization.
So if you ran it back through a high temperature kiln and de-hydrated it. You would have a powder.
2006-09-11 15:12:13 · answer #1 · answered by Roadkill 6 · 0⤊ 0⤋
I'm no expert, but I was of the impression that concrete is basically dehydrated limestone. When it cures, it's basically absorbing water into it's molecular structure. I believe it "un-cures" when baked at high temperatures. There was a train wreck and fire under a concrete bridge near where I grew up. The bridge's concrete basically disintegrated due to the high temperatures of the fire. You may want to check the wikipedia reference on this subject.. http://en.wikipedia.org/wiki/Concrete
2006-09-11 19:38:37 · answer #2 · answered by billclawson 2 · 0⤊ 0⤋
I would say no, cause it goes through a chemical change. And you are using the wrong terms. Concrete is solid form. Cement is the liquid form.
2006-09-11 19:30:38 · answer #3 · answered by foofoo 3 · 0⤊ 0⤋
no. well, unless you say that hitting up with a big ol' hammer, and useing the big peicese as rock, and the powder as sand.
however, stong acids can dissolve concrete as some concrete mixes are hugely alkinle
2006-09-11 20:14:14 · answer #4 · answered by Daniel 3 · 0⤊ 0⤋