Mat Foundation Mass Concrete Design
Mat Foundation Mass Concrete Design
(OP)
I am working on the design of a 90'x60'x3' mat foundation and am looking for some recommendations for concrete parameters as it relates to mass concrete and construction detailing.
I'm considering one pour using type 2 cement, low w/c ratio, 3,000 psi strength. I believe I need to require insulation blankets to control differential concrete temperatures.
What other considerations should I make? Should I request thermocouples to monitor inside temperature? How long should the blankets be in place? I haven't seen any guidelines for that.
Thanks
I'm considering one pour using type 2 cement, low w/c ratio, 3,000 psi strength. I believe I need to require insulation blankets to control differential concrete temperatures.
What other considerations should I make? Should I request thermocouples to monitor inside temperature? How long should the blankets be in place? I haven't seen any guidelines for that.
Thanks






RE: Mat Foundation Mass Concrete Design
www.SlideRuleEra.net
RE: Mat Foundation Mass Concrete Design
As SlideRule mentioned 3 foot thick mat is not that massive. Curing is the big trick. I am old school and still like to use the jute blankets or mist spray. Curing concrete properly and taking care of it pays off big time in the long run.
Regards,
Lutfi
www.cdeco.com
RE: Mat Foundation Mass Concrete Design
They recommend thermal blankets to keep the exterior temperature from deviating from the interior temperature by more than 36 deg. F. This is to prevent thermal cracking during curing. I was wondering how long it should stay on.
RE: Mat Foundation Mass Concrete Design
www.SlideRuleEra.net
RE: Mat Foundation Mass Concrete Design
Use of thermocouples or any devices is a comlpete waste, which give you only data, not control. If you are that concerned, use chilled concrete(<10 deg C) and use blankets during curing.
Ciao.
RE: Mat Foundation Mass Concrete Design
Are most redimix plants able to give chilled concrete?
RE: Mat Foundation Mass Concrete Design
I think PCA book gives the method to compute temperature rise. You will also need to contact cement manufacturers for calorific curve of cement.
One particular thing that is mostly heard in such applications is Fly-Ash concrete. I have never used it, but seen in promoted in big way.
Ciao.
RE: Mat Foundation Mass Concrete Design
Ice is great for keeping the concrete temperature down during placement (say for 90 minutes, or so). However it is of no value in controlling temperatures during curing.
Fly ash (included in Type IP cement) helps slow the heat generated during hydration, but Type II cement does the same thing.
During electric power plant construction (mass concrete, up to 18 feet thick) in SC we have had the opportunity to use plenty of both. On the hottest days, used just ice flakes, no (liquid) water at all in the concrete mix. Started using fly ash in concrete in the 1970's - (at that time its use was not common). My company, the electric utility, produced and sold fly ash as a waste byproduct of burning coal - we wanted to promote the use of fly ash.
www.SlideRuleEra.net
RE: Mat Foundation Mass Concrete Design
I would require the supplier to provide a mix design they have used in the past for similar applications with all the breaks along with any other data they took on it. I would suggest having a conference before pouring with the concrete supplier and general contractor.
Craig