Road salts are a universal solution for removing snow or frost from a surface. It’s a simple way to eliminate snow and also prevent further accumulation for some time.
It’s no surprise then that people are unaware of the damage salt can do to concrete—or at least until it’s too late.
How can salt damage your concrete?
Salt is a deicer that’s used to get rid of ice, snow, or frost from an area. The effects of deicers on concrete are relatively complicated. Extensive research has been done on this subject in recent years.
Here are the basics of how deicers affect the durability of concrete.
Aggravate freeze-thaw scaling damage: The general misconception is that concrete is a solid block of mass; however, it is quite porous and quite quick to absorb water and other liquids. When the liquid freezes, it undergoes expansion and exerts a force on the surrounding solid. This leads to cracking, and the concrete becomes weaker.
If deicers, such as salt, are present along with the water, this process is aggravated, causing further damage. High-quality concrete is impervious to freeze-thaw damage because it is air-entrained.
What this means is that there are tiny air pockets in the concrete that allow extra space for water to expand.
Direct chemical attack: Deicers can chemically react with the concrete and cause it to crack over time. Chemical reactions can occur with the cement hydration products or the aggregates, which can cause irreversible damage.
Rebar corrosion: Road salts can also cause corrosion of the rebar and steel-reinforced concrete. When rebar corrodes, the iron in the steel is converted to iron oxide. The creation of this new compound causes expansion. Because the rebar is encased in concrete, there’s very little room to accommodate that expanding product.
So as the rust layer grows, it exerts pressure on the concrete matrix, which causes it to crack over time.
How to protect your concrete from salt damage?
There are two things you can do to protect concrete from further damage.
Water repellant sealer: Look for a siliconate water repellent or a silane siloxane water repellent. Using a pump sprayer, layer the surface of the concrete generously with the repellant. The repellant will act as a barrier and will cause water to bead off the surface instead of absorbing.
Protective coating: Acrylic sealers can protect concrete from further damage. They form a protective film on top of the concrete. Deicers can decrease their lifespan, but you can expect to go about 4-5 years before a redo.
Professionals in concrete repair can help you achieve better results because they have the right tools and years of experience. At AMN Masonry, we offer superior concrete repair and restoration services in the greater Boston area.
We start by testing samples of concrete to determine its quality. After the consultation, we determine the best course of action for repair. Using specialized tools and experienced technicians, we restore your concrete structures. We also offer waterproofing services to protect your concrete from further damage.
For a free estimate, call us at (774) 244-8248 or fill this form.