pH is a critical factor in the chemistry of concrete. Portland Cement, the “binding” component in concrete (the other components being sand, rock [aggregates] and water) has a pH approaching 11, which is very alkaline. If you remember your high school chemistry, neutral pH is 7. Above 7 is alkaline, and below 7 is acidic. In order for the cement to hold together the other components, it is important for it to remain at or near a pH of 11.
When salt (pH of roughly 5) or other acids are introduced onto (and therefore “into” as well) the concrete, they enter into the small pores and micro-cracks of the concrete and attack the surrounding materials, lowering their pH. As the pH is lowered, the cement’s ability to hold things together is compromised. Exposed to acidic environments for a long enough period of time, and all that will be left is sand and rock.
A good indicator of the level of degradation in your concrete is a pH test. We use a digital pH meter, which instantly reads the pH in the concrete. If your concrete’s pH is between 9 and 11, you are in pretty good shape (and your concrete probably looks pretty good as well). pH between 7 and 9, and the concrete is starting to break down. You may notice some surface damage at this level – but not always. pH around 6, and you certainly have visible damage. pH readings below 6, and you have severely deteriorated concrete. If your pH reading is around 4, you will need to replace the concrete, for there is little left to hold it together.
CreteDefender penetrates and fills the pores and micro-cracks of concrete with a solution that forms a gel and hardens. The pH of this gel is roughly 11 – the same as the surrounding concrete. This raises and stabilizes the pH in the concrete – permanently, and the hardened gel prevents the intrusion of salts, acid, or other chemicals.
