It’s Porous
Concrete is, somewhat surprisingly, porous. While it is very hard, it also has millions of tiny pores and microscopic cracks.
Under a microscope, concrete looks more like a sponge than a rock.
Salt, Water, and Other Chemicals
Get in the Pores and Break it Down
Salts, chemicals, and freeze/thaw cycles compromise concrete.
Salt and water get into the pores of the concrete and attack the bonds. Water gets into the pores and expands up to 18% when it freezes. This pressure pops off the surface of concrete, exposing the rocks, and creating
an unattractive look and a potential safety issue.
Salt Is Acidic, Concrete Is Alkaline
Salt is especially bad for concrete because it is slightly acidic, and reacts with a highly alkaline concrete, breaking the bonds holding the concrete together.
Given enough time, this reaction will reduce the concrete to sand and rocks.
You can tell when this damage is occurring by measuring the pH of the concrete. Healthy concrete has a pH of 10 to 11. Lower pH levels indicate the deterioration is under way.
Poor Installation Makes Concrete Vulnerable to Damage
Engineering concrete is a lot more complicated than one might think. A lot of attention is paid to curing conditions, but most of the damage to concrete is started when the mixture is made. Concrete contains 4 basic ingredients: Portland cement, sand, rocks, and water. The proportions of these ingredients are critical to the strength and performance of concrete. If these proportions are off, even a little bit, concrete is compromised. The most common issue is adding too much water to the mix to make it easier to work. Too much water weakens the concrete and creates a pore structure that invites damage. Even concrete that is installed correctly can be compromised by salt, chemicals, and freeze/thaw cycles.
The key to protecting your concrete is to first have properly mixed and placed concrete, and then to prevent salts and water from entering the concrete. CreteDefender™ permanently prevents salts and water from entering the concrete.
