Concrete structures in cold climates, like wet roadside curbs, retain moisture, making them vulnerable to frost action and subsequent damage.
The de-icing salts used in curbs draw more water into the concrete, worsening the damage during freeze-thaw cycles as temperatures fluctuate.
The primary issue arising from frost action is surface scaling, where water penetrates the porous structure of the concrete and remains inside.
As the temperatures drop and the water freezes, the expansion of frozen water exerts pressure on the concrete. This pressure can cause the outer layer of the concrete to crack and chip off.
Another significant problem is D-cracking, a type of damage near the edges and joints. These D-shaped cracks indicate deeper structural problems, threatening the concrete's strength.
Concrete lacking air-entrained voids, which provide space for water expansion during freezing, suffers severe damage from repeated freeze-thaw cycles.
Each cycle causes the concrete to expand, leading to further cracking and eventually to spalling, which is a destructive process, that detaches concrete fragments from the structure and significantly reduces the structural strength of the concrete.
