How long for concrete to cure....?


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Old 01-19-15, 08:54 PM
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How long for concrete to cure....?

So this is more of an argument.
Pouring 5 inch thick slab for garage floor...current temperatures just a few degrees above freezing and the garage, while covered won't be much warmer.

I say, it should cure longer than 48hrs in order to really ensure it will last long.
My friend says that as long as it isn't freezing, it doesn't matter if it is 40F or 60F....it will cure at the same rate.

Who is right ?

thanks!
 
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Old 01-20-15, 06:32 AM
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Well, they say the concrete in the Hoover Dam is still curing.....

Here's some interesting reading:

Curing in Construction

http://www.concretenetwork.com/cold-...te/curing.html
 
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Old 01-20-15, 08:40 AM
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Concrete curing is exothermic chemical process. It's curing rate is determined in part by the temperature. Hotter concrete cures faster and cooler cures slower. The first article The Tow Guy linked has a good chart showing the relationship. Even the difference between 40f and 60f has about a 100% difference in the curing rate.
 
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Old 01-24-15, 01:52 AM
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imo, if you don't have o'nite temps in mid 40's OR insulating blankets, its too cold to place conc for the avg diy'er,,, that being said, dump the mud on UNFROZEN ground, place, finish, install jnt pattern, close the door, & turn on the heat so you get 50f most specs say 40f & rising for proper conc placing & finishing
 
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Old 01-24-15, 10:28 AM
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But don't go overboard with applying the heat to an enclosed area. While it's not very likely, you can do just as much harm if you bake the slab's surface while the interior is still fluid (and cooler), removing moisture from the mix needed for proper hydration. Excess shrinkage cracks and poor surface durability are things you want to avoid on any slab, but especially a garage floor.
 
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Old 01-24-15, 02:35 PM
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good point, bdge,,, had anticipated the op would use a thermostat idiot me, huh ?
 
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Old 01-24-15, 05:37 PM
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Very few of us working-class grunts have the luxury of garages with temperatures controlled by thermostats (implying a furnace). Most would just fire up a few portable heaters, and hope for the best. If lucky, maybe a wall thermometer to keep track of things.

Hence my suggestion to avoid overheating the new concrete.
 
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Old 01-26-15, 01:47 PM
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thermal blankets and hot air blowers would be the solution for me.....I can't wait till it hits above 40F so planning to do it once I get in high 30s / low 40s.
Of course 40s during a day usually means 30s at night.
 
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Old 01-26-15, 03:13 PM
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salamanders ( kerosene or propane ) have thermostats - usually on a 10' cord,,, or ours do
 
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Old 01-26-15, 03:26 PM
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When I moved to northeast tenn nobody knew what a salamander was most around here call them jet blowers I've only seen the thermostat cord attachment a time or two but I never thought it was that big of a deal to plug/unplug the heater as needed ....... but then it doesn't take paint as long to dry as concrete
 
 

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