Rant: Just found out how much water weight a yard of concrete actually loses

I was reading an old trade manual from the library (the one with the cracked blue cover, you know the one) and it said a standard yard can lose up to 150 pounds of water during curing. That's like a whole person just evaporating out of the slab. I've been doing this for years and never really thought about the actual numbers, just the timing and the finish. It makes total sense why those early morning pours in Phoenix dry so much faster than my afternoon jobs. Has anyone else seen a weird fact about the material that made you rethink your timing on a job?

3 comments

3 Comments

jessicahill1mo ago

Totally get it. I saw a breakdown once about how much heat a big pour actually makes as it cures. It blew my mind. I had a winter job where we had to tent and heat the slab, but the pour itself was putting out so much heat we almost cooked the thing. Made me completely change how I plan for cold weather blankets now. You stop thinking of it as just wet rock after that.

the_leo1mo ago

It's wild how much that chemical reaction can actually overheat things.

emma_young13d ago

That whole 'stop thinking of it as just wet rock' thing is so true... it really changes how you look at a pour once you see it happen. @the_leo you're right about how wild it is, because I've seen slabs actually crack from the heat if you're not careful. It's like the concrete is cooking itself from the inside out, and you gotta plan for that extra warmth even when it's freezing outside. People don't realize that big pours can heat up way more than you'd expect, especially in colder weather when you think you need extra heat from the blankets. It's a total balancing act... too much heat from the pour plus your heaters and suddenly you're fighting to keep it from overheating instead of freezing.