ABSTRACT
Corrosion of reinforcing steel in concrete is often the limiting factor in the service life of concrete structures (Cady [1977]). This ought not to be so as good quality concrete
covers were known to have protected steel bars against corrosion for long periods of time even under severe exposure conditions. In addition to providing an effective physical barrier against the invasion of deleterious substances, a good quality concrete cover provides a highly alkaline environment conducive for the passivation of embedded steel. There are two general mechanisms by which this highly alkaline environment and the accompanying passivating effects may be destroyed:
(a) Reduction of alkalinity by leaching of alkaline substances or partial neutralization by reaction with carbon dioxide.
