Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-18-2011, 12:00 PM   #1
Newbie
 
Join Date: Dec 2011
Posts: 1
Share |
Default

Concrete setting time


Hi I was wondering if anyone can help me,
I'm pouring a slab of 20mpa concrete and I'm not sure how long I will need for it to set enough to have medium to heavy traffic on it!!

Rondo84 is offline   Reply With Quote
Old 12-18-2011, 12:39 PM   #2
EIT/DIY'er
 
Join Date: Oct 2011
Location: Western NY
Posts: 51
Default

Concrete setting time


Depends.

Talk to your supplier. Concrete can be ready for traffic in 45 minutes, or after 2 weeks of wet curing. It all depends on the mix.

Lattimer is offline   Reply With Quote
Old 12-18-2011, 12:40 PM   #3
Newbie
 
Join Date: Dec 2011
Location: Brentwood, CA
Posts: 23
Default

Concrete setting time


Of course it all depends on moisture and temperature, but the rule of thumb if that you can walk on the concrete after 24 hours; it will gain around 2/3 of it's full strength in a week and another 2/3 after 4 weeks total curing time. It will actually keep on curing and gaining strength for many years. It's typical to allow foundations to cure at least 3 days before framing on them. Also, note that curing time is extended around 1/3 for every 10 degree drop in temperature, with the optimum temp at between 65F and 80F.
dave54 is offline   Reply With Quote
Old 12-18-2011, 01:01 PM   #4
Member
 
concretemasonry's Avatar
 
Join Date: Oct 2006
Location: Minneapolis/St. Paul, Minnesota - Latitude 45.057 Longitude -93.074
Posts: 3,645
Default

Concrete setting time


Keep in mind that the rate of curing depends on the temperature of the concrete and not the air temperature.

Dick
concretemasonry is online now   Reply With Quote
Old 12-18-2011, 04:18 PM   #5
Tileguy
 
Bud Cline's Avatar
 
Join Date: Mar 2006
Posts: 9,124
Default

Concrete setting time


Quote:
it will gain around 2/3 of it's full strength in a week and another 2/3 after 4 weeks
Bud Cline is offline   Reply With Quote
Old 12-18-2011, 04:50 PM   #6
Member
 
concretemasonry's Avatar
 
Join Date: Oct 2006
Location: Minneapolis/St. Paul, Minnesota - Latitude 45.057 Longitude -93.074
Posts: 3,645
Default

Concrete setting time


Bud is right -

Concrete itself will gain heat from the curing (heat of hydration, technically) that keeps the concrete temperature up for curing. What you do to maintain the heat is up to you (poly, blankets, sun exposure, etc.), but for that strength of concrete, whatever is done in a reasonable climate will be enough.

In most cooler climates, at this time of the year, heated concrete is normal or available at minimal cost to provide the "jump-start" that precludes the minor cost inconveniences.

Dick
concretemasonry is online now   Reply With Quote
Old 12-18-2011, 04:50 PM   #7
journeyman carpenter
 
woodworkbykirk's Avatar
 
Join Date: Sep 2011
Location: nova scotia canada
Posts: 2,593
Default

Concrete setting time


so its at 4/6 of full strenght between the end of the first week up to the start of the 4th week? when does it get to 5/6 ????


if its for a slab you can walk on it after about 24 -30 hrs.. but dont drop anything on it its not fully cured. concrete reaches near full strenght after 28 days in optimal conditions
woodworkbykirk is offline   Reply With Quote
Old 12-18-2011, 07:37 PM   #8
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 3,984
Default

Concrete setting time


Concrete strength is generally quoted based on 28 day cure, so for example 3000 psi concrete (English units) is designed to reach 3000 psi after 28 days, however after several years the concrete may well reach 5000 psi or even higher. Early cure mixtures use special chemicals to accelerate curing, and can reach 50 percent of 28 day strength in as little as 8 hours. Unless you know the specifics of your mix, you should be conservative in assumptions about strength after less than 28 days.
Daniel Holzman is online now   Reply With Quote
Old 12-18-2011, 08:09 PM   #9
Member
 
Msradell's Avatar
 
Join Date: Sep 2011
Location: Louisville Kentucky
Posts: 858
Default

Concrete setting time


Quote:
Originally Posted by dave54 View Post
it will gain around 2/3 of it's full strength in a week and another 2/3 after 4 weeks total curing time.
Quote:
Originally Posted by Bud Cline View Post
Yes, Dave's statement is correct the second 2/3 is an approximation of how much of the remaining strength will be obtained. Thus 2/3 of the total in the first week in and 2/3 of the remaining 1/3 in the next three weeks. So an approximation of the strength after four weeks is 8/9 of the ultimate strength. Of course as stated before the mix makes a big difference.
Msradell is offline   Reply With Quote
Old 12-18-2011, 09:02 PM   #10
Newbie
 
Join Date: Dec 2011
Location: Brentwood, CA
Posts: 23
Default

Concrete setting time


Thanks for the clarification, Msradell. I was referring to 2/3 of the remaining 1/3, in weeks 2, 3 and 4, which for all intend and purpose means about 90% of full strength in 28 days.

dave54 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Repairing concrete slab in shower JohnRoss Building & Construction 0 08-08-2011 01:20 PM
Fan setting reads AUTO and ON at same time on Honeywell 8500 thermostat Studly HVAC 1 03-21-2011 08:27 PM
epoxy coat and resurfacing concrete cure time questions ?? waltereo Flooring 3 10-04-2008 11:43 AM
How to smooth a rough aggate concrete floor lotstodo Flooring 1 08-18-2008 09:23 PM
Setting 3/4'' wedge anchors in concrete slab George Webb Building & Construction 4 02-27-2008 03:11 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.