Heard a wild fact about concrete curing at a supplier in Phoenix

I was picking up a load of 4000 psi mix from Arizona Materials yesterday and the yard guy told me concrete actually gains most of its strength in the first 24 hours, not over weeks like I always figured. He said it hits about 70% of its rated strength in that first day, which blew my mind. Is that actually right, and does it change how you guys handle early finishing or wet curing?

3 comments

3 Comments

martinez.diana26d ago

Wait, only 24 hours?

mason_lee25d ago

Yeah that's totally right, it's wild how fast it happens. I mean idk the exact numbers but that 70% in a day sounds about right from what I've seen. Had a crew pour a slab last summer and we were walking on it the next morning, no problem. It really does make you think about getting that finish work done quick before it sets up too much. Maybe it's just me but it changes how you watch the weather too, like a hot day in Phoenix will speed it up even more.

wesley834d agoMost Upvoted

So does that mean the last 30% takes weeks to get? What's going on in the concrete during that long tail?