# Anyone know how long it takes concrete poured for a sidewalk to harden?



## FrankZubek (Aug 31, 2010)

Its for a story and concerns a few kids who use sticks to mark their names in the hardening cement the way kids tend to do and yet my story needs them to return later on and ADD a little inscription to it. I need a timeline from when the construction guys lay the material to when it's no longer possible to easily use a stick to carve a name into it before it permanently harden.

So........anyone have a construction worker in the family?


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## cinisajoy (Mar 10, 2013)

Depends on the concrete, temperature, and humidity.  Probably at most 2 hours.


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## AngryGames (Jul 28, 2013)

I poured concrete curbs and slabs for while back in my very early twenties, but it was in FL. Temp has a lot to do with it, humidity can too, but not as much. If I remember right, the Hoover Dam still has concrete that is curing to this day...

but cin is right...about two hours and it will be not 'set' but it will start becoming rigid (and flaky around the surfaces if you scratch at it).

You can also check this:
http://www.stanleytools.com/xhtml/p_concrete.htm


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## ruecole (Jun 13, 2012)

Hubby works in construction. He says, "Maybe two hours."

Hope that helps!

Rue


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## gljones (Nov 6, 2012)

Funny you should ask.  I just had a sidewalk poured a month ago, and I had to stay off it for at least an hour after it was poured.
It was finished off with standard "Broom" finish.  This is pretty standard.  The contractor said to be safe don't do any twisting and turning on it for 24 hours as you may mess up the broom grooves.
If someone wanted to carve initials into the concrete, it would have probably have to be in the first hour.

I sat out on my porch and cleaned my shotgun while it was drying. 

For some reason none of the neighborhood kids tried anything.

Just kidding folks...


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## FrankZubek (Aug 31, 2010)

Thanx
I thought of a story this afternoon about two kids who carve their names in the wet cement and then I have one of the kids get stabbed or shot a few blocks away and his buddy finds out- realizes the cement is drying and hurries over to the block of cement and he writes in THAT DAY and date as the day his buddy died. So the block of wet cement becomes a kind of memorial for the other kid who died.

At least that's the core of the piece.
I don't want to say much more for now but I did want to have that timeline at hand so when I write it I know the timeline. So..... thanks to all.

Gotta love kboards!


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## PeggyI (Jan 9, 2011)

Standard concrete at 80 degrees 1 hour using your finger or a stick, 2 hours carving with a knife.

(14 years working for Lafarge, including 4 yrs driving a mixer and 2 yrs training drivers.)


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## FrankZubek (Aug 31, 2010)

Peggy--  so the concrete is 80 degrees or are we talking a typical summer hot day?


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