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Is it safe to use deicing salts on concrete,
asphalt and wood surfaces? Can Deicing salts
cause severe damage to concrete? Are there
safer salts that work differently than others?
What about using fertilizer as a deicer
and traction aid? Read on and find out the
real story and what your snow contractor
should be using to protect your roads and
walks.
Damage to Concrete
Deicing salts can cause severe damage to
concrete that has not been formulated, mixed,
installed and finished properly. That is
a fact. The good news is that it is easy
to install concrete so that deicing salts
can be used with confidence knowing that
little or no damage will occur over the
years.
The damage to concrete is actually caused
by the freezing and thawing of water that
soaks into the upper surface of the concrete.
The use of deicing salts increases the amount
of freeze-thaw cycles that a concrete sidewalk
or driveway experiences. The volume of water
increases by 9 percent when it freezes.
This expansion creates internal pressures
that can break apart weak concrete.
What You Can Do: Proper Concrete
Installation
Make sure your properties have proper concrete
installed on walk ways and roads. Concrete
that contains small air bubbles (air entrained),
a minimum of 564 pounds of cement (6 bag
mix) per cubic yard and a minimum amount
of water when mixed (4 inch slump) can resist
repeated episodes of ice expansion within
the concrete.
In addition, the concrete must be moist
cured at or above 50 F for a minimum of
seven days, produce a 28 day strength of
4,000 pounds per square inch and have a
minimum drying time of 30 days before it
is subjected to the first freeze-thaw cycle.
These practices are commonly followed by
experienced, professional concrete masons.
How About Wood?
Deicing salts rarely cause problems on
wood surfaces and asphalt besides some discoloring.
What little damage may be caused is far
outweighed by the benefits of preventing
personal injury as a result of a fall on
ice.
Preferred Products to Use on Walkways
Not all salts are equal. Your contractor
should be using Magnesium Chloride on your
walks. This product continues to melt the
ice to -13 degrees. This reduces the number
of thawing and re-freezing cycles –
reducing damage to your walks. Be sure your
contractor uses 100% magnesium and not some
combination with other salt products.
Preferred Products to Use on Roadways
In this area we generally use a combination
of sand and a salt product. Sand provides
a good deal of traction and no damage to
the roads. In colder markets in the North
some contractors use salt exclusively. At
this time Blade Runners recommends 60/40
sand to calcium chloride mix.
See below a comparison of different
products:
| Item |
Low
Melt Temp |
Cost
per 50lb bag |
PROS
|
CONS |
| Rock
Salt
(Sodium Chloride)
|
16-20
Deg |
|
- Inexpensive
-
Effective
-
Good traction
|
- Harsh
on concrete
-
Can damage landscape plants
-
High amount of thaw cycles
-
Release maximum amount of chloride
ions (high environmental impact)
|
Potassium
Chloride
(White Potash)
|
20
Deg |
8.50
|
- Safe
on plants
-
Little Residue
-
Inexpensive
|
|
Magnesium
Chloride
|
-15
Deg |
15.00 |
- Fast
acting
- Very
low thaw cycles
-
Safest for concrete
-
Low environmental impact
-
Less toxic to plants than all others
|
- Can
corrode aluminum/steel over time
- Blade Runners recommends
this product.
|
| Urea |
20-25
deg
|
7.00
|
- Does
not contain plant harming chlorides
- Inexpensive
|
- Very
High thaw cycles
-
Can cause fertilizer burn to plants
-
Ammonium nitrate and sulfate provide
highest threat to concrete.
|
Calcium
Chloride
|
-15
deg
|
11.00 |
- Low
thaw cycles
-
Attracts moisture from atmosphere
|
- Can
leave oily residue
-
Expensive
-
Need 2x the product as compared
to magnesium
|
| Potassium
Acetate |
-15
deg |
|
- Pre-treatment
application
- Reduce
need for shoveling labor
|
- New
product potential unknown issues
- Expensive
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New Products on the Horizon
There is a line of pre-treatment deicing
products that Blade Runners is going to
test this coming winter. This would involve
a liquid application on roadways in advance
of a storm to reduce accumulation of ice.
The manufacturers claim zero potential damage.
Blade Runners will keep you posted on the
results and further research.
Blade Runners Snow Plowing Information
Letter
Follow the attached link to see about our
plowing technique and most common concerns
of residents.
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