Pouring Concrete when temp is 25 F
Pouring Concrete when temp is 25 F
(OP)
I have not dealt with cold weather concreting too often. Now I have a situation that the contractor want to start pouring early tomorrow (slab on grade) when the temp is supposed to be around 25 F, but then it is supposed to raise up to mid 40s. The next two days look good with low forecasted at 37 and highs in the 50s.
So my question is, other then following the typical guidelines for cold weather concerting (ground not froze, no snow on ground, aggregates and water being heated, using a non-chloride accelerator), should I be concerned about any other issues. The contractor has obviously dealt with similar situation many times in the past so he is experienced with cold weather concreting. Also, is there a minimum temperature below which they should not pour concrete?
So my question is, other then following the typical guidelines for cold weather concerting (ground not froze, no snow on ground, aggregates and water being heated, using a non-chloride accelerator), should I be concerned about any other issues. The contractor has obviously dealt with similar situation many times in the past so he is experienced with cold weather concreting. Also, is there a minimum temperature below which they should not pour concrete?






RE: Pouring Concrete when temp is 25 F
RE: Pouring Concrete when temp is 25 F
Follow the guidelines for the condition of the base and the temperatures of the mixed materials. Heated aggregates a somewhat uncommon in most areas and are usually not too warm. Mixing water can be very efficient to trigger the cement heating and generation of the heat of hydration that should be contained, but limited but can easily be reduced in real cold weather, by just removing any insulation. Protection of the finished concrete economical and is critical for it to obtain the strength expected.
I have been on projects where large pours were done at -30F without a problem because of preparation, logistics and control of materials and whatever protection that was required later.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Pouring Concrete when temp is 25 F
RE: Pouring Concrete when temp is 25 F
And keep it covered - you can even use "warm" water spray to maintain temp.
RE: Pouring Concrete when temp is 25 F
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Pouring Concrete when temp is 25 F
considering the temps are to drop even further in the coming months, if we don't do it now, we'll have to wait till spring to pour concrete.
Mike,
Its a SOG for a church. The slab will eventually be covered with tiles and carpeting. And yes, they now that they have to keep it covered. I told them that 55 F is placing temp they have to maintain and they have to keep this temp for 3 days after the pour.
RE: Pouring Concrete when temp is 25 F
The contractor is expereinced in cold weather concreting, the mix design seemed to be geared up for the conditions. Also, the air temp this morning at pour time is 30 F and is supposed to warm up to at least high 40s later today. 50s high over the weekend.
RE: Pouring Concrete when temp is 25 F
RE: Pouring Concrete when temp is 25 F
Please distinguish between the temperature of the air and the temperature of the concrete during placement and while curing.
www.PeirceEngineering.com
RE: Pouring Concrete when temp is 25 F
Make sure the subgrade isnt frozen before, then just follow guidelines.
RE: Pouring Concrete when temp is 25 F
intelliRock II™ - Concrete Maturity, Temperature, and Moisture Measurement System
The unit is about $3,000 and the probes are $55 each. They get embedded in the concrete, so they are one use only. You can get temperature only or maturity probes. Recommend several probes in the concrete and at least one for surface air measurement
http://www.engius.com/web/products/intellirock.asp