Cold weather concreting idea.

[RDK]

I recently bought a couple of RV furnaces for my construction site trailer. While installing them I thought that they would also be handy for cold weather concreting.

They are available in various sizes from 12,000 to 40,000 BTUH. Run on 12v and propane and weigh less than 25 lbs. I am running one off of a 20 lb propane bottle and an old barbeque regulator and hose. You could power the fan from a car battery or battery charger.

They have zero clearances in some dimensions and the maximum required clearance is 2” The ones I got are less than 10”x10”x24” so they could easily be installed in the hoarding.

They are indirect heating so there is no combustion fumes discharging onto the fresh concrete. They would also be a lot safer than tiger torches and are thermostatically controlled.

The ones I got were from e-bay and are 16,000 BTUH and cost $USD 207 plus shipping.



Rick Kitson MBA P.Eng

Construction Project Management
From conception to completion

http://www.kitsonengineering.com

 

[ishvaaag]

As long as what you make is just heating the fresh concrete a bit in a cold environment it may go fine. I would suggest to heat the gravel or water, rather than the fresh concrete. If not, in looking after your thing, keep vigilant about if the drying air results in unwanted cracks, and maybe some disgregation.

 

[SirAl]

RDK

Thanks for sharing the idea. The ability to thermostatically control the heat of the enclosed space is good. Now, if we could only ensure the delivery of enough heat on those -45C nights that are sure to arrive in the coming months.

 

[RDK]

Here it is common to do cold weather concreting at temperatures as low as –30C or so. I have actually been involved in one pour at –38C (Keeping the air pot from freezing is sometimes a bit of a trick.) Yes, we heat the gravel and water but the problem is that the enclosure must be heated for 7 days.

These RV furnaces may be too small for any large pours but they would suffice for smaller pours. I have actually seen contractors use full sized 100,000 BTUH house furnaces. The problem is that these units provide a lot of heat but require ductwork to distribute the heat evenly throughout the forms.



Rick Kitson MBA P.Eng

Construction Project Management
From conception to completion

http://www.kitsonengineering.com