| When placing concrete in cold temperatures, a
contractor can pour without adding heat and hope the concrete cures properly or add
adequate heat and know the concrete will cure properly. Rather than bank on the fickleness
of nature, most contractors will opt for some form of heat application. But there are many
methods available and most are quite costly. Ground Heaters, Inc., of Spring Lake,
manufactures several models of heaters that can greatly increase construction
productivity by allowing equipment and crews to keep working all year long. One of its
most popular models, the E3000, can thaw up to 6,000 square feet at a rate of one-foot
deep per day. It has proven very useful for arctic applications, such as pipeline
maintenance in Alaska, but here in Michigan the Ground Heater has allowed contractors to
virtually eliminate the concept of a "construction season".
TESTED AND PROVEN
Agricultural Building and Design (AB&D), an Okemos-based contractor, constructs
commercial sized dairies in Michigan, Ohio, and Indiana. One strong tenet of the
company’s philosophy is to provide its employees with the best available construction
equipment and tools. The belief is that by doing this, AB&D will be able to provide
its customers with the best structure. Although Agricultural Building and Design strives
to complete concrete placements before the arrival of cold temperatures, it’s not
always possible.
After learning about the Ground Heater’s ability to thaw frozen ground and cure
concrete in cold weather, AB&D immediately recognized the value to its operations. The
heater is now an essential piece of equipment for their fleet. AB&D initially rented
an E3000 Ground Heater from the Michigan CAT / Ground Heater Dealer in Holt, but soon
after using it decided to purchase one for their equipment fleet. "We usually have
about ten jobs under construction at once, so owning this heater insured it would
definitely be available when we needed it," said Dawn Rhodes, President of AB&D.
"The easy portability of the trailer-mounted E3000 allows us to quickly move it
around a job site, as well as from one project to another." The first job AB&D
used the Ground Heater for was the Hart Dairy Project in Clayton. "We first used it
to thaw the ground so we could pour concrete for feed alleys, drinker floors, and the
outside apron," explained Rhodes. "Then we placed a poly vapor barrier, the
E3000’s hoses, and then insulation blankets on top of the set concrete to provide
heat for proper curing. It worked great and allowed us to keep the project on
schedule."
BETTER THAN EVER
In response to customer requests, Ground Heaters, Inc., has fully modified the E3000
Ground Heater unit. The new performance features include an oil-line heater for easy cold
starts, increased combustion efficiency, simplified warm-up procedure, hitch option,
roll-up doors, and a new control panel. These upgrades further enable contractors to thaw
building sites and cure concrete all winter long, even in the coldest weather conditions.
This helps to complete projects in less time and at reduced costs.
To ensure cold-weather starts, a heater was added to the E3000’s fuel line. The
heater warms the fuel, which results in smoother starts. In addition, a smaller fuel
intake nozzle further increases combustion efficiency. An auto-bypass valve is included on
the heat transfer fluid pump, which simplifies the warm-up procedure. With previous
models, valves need to be manually released while throttling the engine to prepare the
unit. The warm-up process is now as simple as starting the unit and letting it run.
The E3000 can also heat up to 12,000 square feet
of ground, indoors or out, to prepare the ground for concrete placement, to prevent frost
penetration, or to assure proper curing of the concrete. The E3000’s flexible hose
allows curing of all types of concrete placements: slabs on grade, elevated slabs,
columns, and poured walls. Preheating the ground to approximately 85 degrees F gets the
concrete hydration process off to a good start and assures the slab will set in
approximately two to six hours. It also has an adjustable temperature controller, which is
very important for the temperature sensitive process of concrete curing. Concrete should
never be poured on ground or into forms that are below 55 degrees F, nor should it be
poured onto ground that is too hot. The E3000’s temperature controller allows the
user to raise or lower the temperature to the desired level to ensure timely setting and
proper curing.
The Ground Heater comes equipped with 3,000 feet of heat transfer hose,
which is laid out in loops about 2 feet apart on the frozen ground. The
unit's’305,000 BTU's per hour hydronic heater warms the propylene glycol fluid up to
180 degrees F. To make it easier to refill the hose with heat transfer fluid, the
hand-operated refill pump has been replaced with an electric pump. Two pumps circulate the
heat transfer fluid through the hoses and conduct dry, radiant heat directly into the
ground, concrete, or work space. The flexible heating hoses can be placed alongside
footings to protect them from heaving due to frost penetration. The hoses can also be
strung in long, parallel lines to thaw trenches or laid in any needed configuration. For
areas where the ground is frozen especially deep, such as parking lots and roadways,
thawing can be greatly accelerated by using Ground Heater’s patented siphon probes.
These probes make is possible to thaw to a depth of 55 to 60 inches in as little as 3 to 4
days.
With a 72-hour continuous run time, the unit does not require constant refueling and
that keeps workers out of inclement conditions. The Ground Heater’s deep thaw
capability can thaw up to ten feet deep in a single application, meaning further
excavation and resetting of the unit is kept to a minimum. Additionally, because the
hydronic heater isn’t pressurized, there is no requirement to constantly monitor the
equipment as with steam heating options.
The E3000 provides temporary heating for enclosed buildings until a permanent heating
system is installed. However, unlike propane salamanders, the E3000 does not discharge
water vapor or carbon dioxide into the workspace. Other E3000 modifications include a
height adjustable ball or pintle hitch option, convenient roll-up doors and an improved
control panel. Hinge-style doors have been replaced by new roll-up doors, which perform
better in windy conditions. The improved control panel now automatically disconnects from
the battery when the machine is not in use, minimizing power drain.
AN IMPORTANT EXTRA BENEFIT
"The Ground Heater has enabled our company to keep customer satisfaction very
high," said AB&D’s Dawn Rhodes. "We can produce quality concrete all
through the winter and complete projects on time because we are not delayed by cold
weather." Now that AB&D can schedule projects right through the winter, the
company has the ability to provide employees with year-round employment. That stability
helps AB&D retain a skilled labor staff.
For more information about the complete Ground Heater product line, call (231)
799-9600, or visit the company’s website at www.groundheaters.com. |
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