Since concrete has been around for so long, and we use so much of it, experts have been able to watch and study how it holds up to time, use, and seasonal change. Let’s take a closer look at concrete’s relationship with ice melt products and how to protect it.
Not All Concrete Is Created Equal
First, to understand how concrete and ice melt interact with each other, we need to establish that not all finished concrete is created equal. Many different factors affect the strength and durability of a concrete pour:
- Ingredient quality
- How it is mixed
- Curing conditions
- What it is being used for
For example, wetter concrete mixes result in weaker cure strengths. Below average ingredients can also leave the finished concrete vulnerable to both physical and chemical damage.
Structural engineers want concrete to stand up to wear and tear, weighted loads, natural disasters, and exposure to the elements for as long as possible. Unfortunately, no finished concrete can endure forever. After time, it will start to show the effects of degradation.
How Does Concrete Get Damaged?
Because concrete is porous, anything present in the environment finds a way in. Most concrete damage is caused by the combination of inferior concrete and repeated freeze/thaw cycles.
The Freeze Thaw Cycle
When moisture absorbs into the concrete, and then freezes, it expands by 9-10%. Over time, this hydraulic pressure of repeated expansion can break down and displace small pieces of concrete.
Concrete itself is very alkaline (around 11 on the pH scale). That means any interaction with substances below 7 on the pH scale can cause deterioration as well. For this reason, you should avoid using ice melt that contains ammonium salts. According to the Portland Cement Association (PCA):
“Most ammonium salts are destructive because, in the alkaline environment of concrete, they release ammonia gas and hydrogen ions. These are replaced by dissolving calcium hydroxide from the concrete.”
Steel reinforcements set within concrete (like rebar) are susceptible to corrosion from moisture and oxidation, which leads to rust. The PCA has also found that:
“when steel corrodes, the resulting rust occupies a greater volume than the steel. This expansion creates tensile stresses in the concrete, which can eventually cause cracking, delamination, and spalling.”
How to Protect Concrete
Each winter, we must balance between protecting our safety on icy paved surfaces, and protecting the pavement itself.
*Tip: you should always wait about a year before you introduce new concrete pours to ice melt products.
Let’s learn a few ways we can mitigate concrete damage while still protecting ourselves from injury during the winter.
The Right Concrete
High quality concrete is much more resistant to damage of all varieties. Here are some examples of measures that can be taken for both new pours and old slabs to protect concrete during the winter.
If you plan on pouring a new slab, use air-entrained concrete. In each cubic foot of air-entrained concrete, there are billions of microscopic air cells. These pockets relieve the hydraulic pressure created by ice expansion. The PCA states that:
“the resistance of concrete to freezing and thawing in a moist condition is significantly improved by the use of intentionally entrained air. Entrained air voids act as empty chambers in the paste for the freezing and migrating water to enter, thus relieving the pressure in the capillaries and pores and preventing damage to the concrete.”
Low Water to Cement Ratio
Concrete mixed with less water cures stronger and is more resistant to freeze/thaw degradation. Follow your concrete manufacturer’s mixing tables to ensure you are not adding too much water to your mix.
Seal Old Concrete
You can further protect older concrete slabs from future damage with an effective sealer. Be sure to thoroughly research and read customer reviews so you can anticipate how well your sealer will hold up over time.
Use Ice Melt Responsibly
Always use a gentle hand when applying ice melt to concrete. Apply a thin layer before a storm hits, then another light layer during the storm as you shovel. Using your ice melt responsibly will not only protect your concrete, but save you money as well.
Use The Right Ice Melt
First, choose a deicer that has chloride salts instead of ammonium salts. Another way to reduce winter concrete damage is lowering the number of freeze/thaw cycles your concrete endures. During the winter, temperatures can rise above freezing during the day and then plunge at night. Use an ice melt that works at lower temperatures so it will keep ice in a liquid state for longer periods of time.
Ice Slicer® produces brine faster and lasts longer than regular white salt, thus reducing refreeze cycles on your concrete. Our all natural, Complex Chloride™ deicer is ammonia free and contains no harsh additives. Instead, Ice Slicer® is made from a balanced blend of over 60 trace minerals that buffer the effects of ice melt on your concrete. These natural corrosion inhibitors are so effective, that in one ASTM B-117 test, Ice Slicer® was shown to be up to 70% less corrosive than white salt.