What is pH and what does it have to do with corrosion of reinforcing steel?
The pH is a logarithmic measure of acidity and alkalinity which is used to express the alkalinity of concrete. Concrete with a pH of 13 is 10 times more alkaline than concrete with a pH of 12 and 100 times more alkaline than one with a pH of 11. Normally no corrosion of steel takes place if it is well covered to protect it from oxygen and if the pH of the concrete is between 9 and 13.