Concrete Curing Time

[Gene Bleuler]

I had a new 4" deep concrete driveway poured last week. How long should I wait before I should drive my sedan on it? What about allowing a small delivery truck (UPS/FedEx) to pull in?

[aemeijers]

Around here, tradition is foot traffic in 24 hours, cars in a week, and no trucks for a month. (and a loaded UPS truck is pretty heavy, one reason they almost always double-park in the street, the others being that backing up takes time and increases chances of an accident.)

But we can't see your driveway and soil from here, and we don't know how the substrate was prepared, and what reinforcing was used. Call the company that put the driveway in. They will likely have very specific instructions as part of their warranty package. Did they cover it during the initial cure with straw or plastic, or just tell you to hose it down daily to keep it from drying too fast? (Or does modern concrete not need that in warmer weather?)

-- aem sends...

[Phisherman]

Concrete fully cures in about a month, but you can drive on it after a day. Keep your drive watered down for a week or two. Pouring concrete is more of an art than a science. Good luck.

[Steve Barker]

if it's been a week, you're good to go.

s

[DanG]

A typical answer would be 7 day minimum for vehicles. I assume they used curing compound and the proper subgrade compaction work as done.

[Jim Elbrecht]

I wouldn't ever let a delivery truck drive on a 4" slab. Isn't 6" standard for driveways? Or is there some newfangled additive that makes concrete stronger?

[or is the extra cost of 2" just so low compared to the whole job that it is just a good idea?]

Jim

[Steve Barker]

ACTUALLY, you be lucky to find more than 3.5" in a driveway. That't the height of a 2x4 thats used for forms. And it's always called 4". Driveways are rarely 6" unless specially ordered that way. And a 4" driveway is plenty strong for any city delivery truck. hell they backed a full load of concrete in on mine to re-do the upper section and no adverse effects.

s

[Robert Neville]

No, it's not a moot point. Air cured concrete has about 30% of it's final compressive strength in 7 days, about 50% after 28 days, and it gradually increases from there over years. As you say, very close to a log function.

It's also important to get the correct mix and reinforcement. Cheap concrete might be 2500psi - better to get 4000psi and then use rebar or steel mesh.

[Tony Hwang]

Hi, I had a concrete pad poured in my back yard to park 7000 lbs. 5th wheel trailer and 3/4 ton PU truck. I parked both after 10 days since pad was poured. Nothing bad happened. Really concrete cures LONG time; ~

100 years, gets harder and harder with time.

[SteveB]

YABBUT .........

It's difficult to find a craftsman nowadays who can cut a grade for a 2 x 4 framed pour that doesn't run from 3.5 to 6 inches thick.

For me, I like to give it a full month before driving on it with a larger than average vehicle. After that, whatever's going to happen will. Just put expansion joints and saw cuts, and roll the dice.

And ......... as an afterthought, a half or full sack mix more than required is cheap insurance.

YMMV, but mine is always right ............ ;-)

Steve

[SteveB]

I worked on a pan crew for high rise buildings. We put in all the forms for the floors. When we did a pour, we had screw jacks underneath the forms, about 8' apart. You could not touch any jack for five days after the pour. After five days, you could remove every other jack. (50%) After one week, you could remove every other jack. After one week, you could remove the remaining jacks.

The concrete in Hoover Dam is still curing. They put water recirculating lines in there that are still functioning and removing heat from the curing concrete, poured in about 1932-1935. IIRC, they projected the concrete would be fully cured in 100 years. By now, though, I would think that the percentage per year would be a percent of a percent.

Steve

[Rich]

I think your right and wrong. The concrete is still curing but the water lines to take the heat away have since been filled with concrete to avoid them being chocked down and when the heat level reached a certain point they forced concrete in them before they were compromised.

Rich

[dougruhlin]

Gene -

Absolutely, 100%, contact the ready mixed concrete producer (or the contractor who placed the driveway, if you believe him to be trustworthy) and ask them! In particular, the ready mixed concrete producer (the firm who supplied the concrete in the truck that was delivered to your project) will be able to tell you, and you should follow their advice by all means! If you don't, you may very well regret it!

------------------------------------- Douglas E. Ruhlin

Environmental / Sustainability Consultant, CCPf, LEED GA, REM, CEA

Resource Management Associates [phone] [e-mail]

[dwasylenko]

IGNORE the answer of driving on it after a DAY... foolish advice.

ya spend $big$ dollars for a nice job... Why would you damage the concrete that should last for MANY years just to drive on it a few days early?

There are molecular structures that have to form... drive on it and you damage those structures, resulted in a failed surface. TWO weeks!

[Rodney]

replying to Phisherman, Rodney wrote: Please do not drive on the concrete after 24 hrs unless you want to risk damaging it!! It is scientific too. The mix , site preparation and application all make a difference to the outcome.. keeping an eye on it and wetting it down in hot weather is a good idea as it prevents it curing too quickly as the water content drops while the chemical reaction is strongest. This helps prevent cracking and crazing. Concrete gets progressively stronger with time , that can be years but is sufficiently strong enough for most domestic usage after 7 days,with care. Once it is cracked,or marked it is permanent. Patience required!

[trader_4]

Given that the post you're replying to is 3 years old, that probably isn't an issue.

[Ed Pawlowski]

I'd still wait another week though beefor driving on it.

[SteveB]

replying to dougruhlin, SteveB wrote: I have been working in the building industry for 25 + years in California. We pour 6" drive approachs on Friday and Drive tractors on them on Monday without any problems.

[SteveB]

replying to dwasylenko, SteveB wrote: We in the construction industry in California give it a minimum of 2 days and most likely 3 days before driving on it. We have driven on them in 2 days and had no problems. We would not do any deliverys tho...

[bob haller]

call the concrete supplier or contractor..........