| Author |
Message |
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt
Post Number: 1134
Registered: 03-2002
| | Posted on Wednesday, October 13, 2010 - 06:24 pm: |    |
Has anyone specified heating a steel deck during the concrete pour? |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 881
Registered: 03-2003
| | Posted on Wednesday, October 13, 2010 - 09:08 pm: | |
Never had to...not much of a problem here in the Phoenix area.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
(Unregistered Guest)
Unregistered guest
| | Posted on Thursday, October 14, 2010 - 02:10 am: | |
Never heard of heating the metal deck and not sure that if it is feasible. If you are placing the concrete in very cold weather ACI has criteria for controlling the temperatures. This could result in enclosing the space and heating it with space heaters.
If this were an issue how it is done would typically be a contractors means and nethods issue.
It wouldn't surprise me that in Phoenix they would spray the deck with water to cool it down. |
Paul Gerber
Senior Member
Username: paulgerber
Post Number: 32
Registered: 04-2010
| | Posted on Thursday, October 14, 2010 - 09:37 am: | |
I was going to say, if it is that cold that you feel you need to heat the steel deck then that is the least of your worries! I'd be worrying much more about how the concrete would ever cure in that situation!
If it is that cold then you definitely need to look at enclosing the area of the pour and getting some temporary heat in the area before, during and after. We pour concrete all year around up here in the great white north eh? and that is the typical method employed (similar to temporarily enclosing and heating sections of exterior wall for installation of masonry veneers). It is not uncommon for admixtures and heat to be added to the concrete at batching, but that and the temporary winter heat needs to be spelled out in the Project Manual. We typically include this in 01500 Temporary Facilities and Construction Controls...errr...01 51 00 or if you go really narrow scope 01 15 23.
Ride it like you stole it!!! |
Wayne Yancey
Senior Member
Username: wayne_yancey
Post Number: 368
Registered: 01-2008
| | Posted on Thursday, October 14, 2010 - 10:54 am: | |
I have similar Canadian experience as Paul. Water temperature was increased in the mix design for pour in the dead of winter in east Kootenays of BC. I cannot remember what else was done to the mix.
I cannot imagine an area in the PNW that would compare to the Canadian winter temps and require such adjustments to the mix design. Temporary enclosures and heat is always good. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 313
Registered: 10-2007
| | Posted on Thursday, October 14, 2010 - 11:45 am: | |
Unless you have reasons for heating the space, other than to facilitate concrete placement, I would suggest that this can be addressed in the cast-in-place concreete section. ACI 306.1 is a specification that tells the contractor on what needs to be done. I do not see any reason to address it in Division 01. You might also want to specify that the contractor submit his plan for review for conformance to ACI 306.1.
ACI also publishes a specification on hot weather concreteing, ACI 305.1. |
Paul Gerber
Senior Member
Username: paulgerber
Post Number: 33
Registered: 04-2010
| | Posted on Friday, October 15, 2010 - 09:18 am: | |
Mark, there are 3 reasons we put temporary winter heat in Division 1...
1) there may be many different trades who need temporary heat at the same or different times. Including this in Division 1 allows us to say it once and say it well and have it apply to concrete, masonry, EIFS or any other building envelope trade which requires environmental conditions control.
2) the Contractor is usually the party responsible for temporary winter heat and with good reason as he is the party to the contract with the Owner and is ultimately responsible to the Owner for the overall quality of the entire finished product, not just one portion of it. These days it is often times hard enough to find competent, dedicated tradesman for their own portion of the work let alone being responsible for something like temporary heat.
3) With one party responsible for the overall winter heat on a project it is usually cheaper for the Owner as the Contractor will make arrangements for larger scale temporary heating systems for the whole winter construction period (such as natural gas powered glycol radiant heat exchangers with fan units) which are much more efficient and do not dump copious amounts of humidity into the work area (especially with interior finishing). It is also cheaper for the Owner because they are not paying for delivery and pick-up of various pieces of equipment and the fuel charges for natural gas are cheaper than propane.
Ride it like you stole it!!! |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 314
Registered: 10-2007
| | Posted on Friday, October 15, 2010 - 01:42 pm: | |
Paul
My comment recognized reason 1 as an exemption.
Regards reason 2: I am of the school that says that says that we do not tell the Contractor how to split up the work. Similarly I leave it to the Contractor to figure out what is the cheaper way. I try to give the Contractor enough flexibility to do what he believes is cheapest. What I believe is cheapest is irrelevant.
I believe that trying to compensate for contractors and tradesmen that do not know their work or do not coordinate is a futile effort. There is no end to the number of issues you would have to address and in the end they would find a new way to screw it up. The real solution is for the Owner to retain a competent General Contractor.
In any case the cast-in-place concrete section is the place to reference ACI 306.1 which has specific requirements regarding temperatures that the concrete sub needs to be aware of. Note that 2009 IBC Table 1704.4 Item 8 requires a special inspector verify the maintenance of the specified curing temperature.
If there is a Division 1 section on temporary heating it needs to be coordinated with the cast-in-place concrete section and the structural engineer. In my experience all too often the structural engineer is not provided with a copy of Division 1 specifications to coordinate and the Architect does not contact the structural engineer to do any coordination. |
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