Performance Monitoring of Cover-Zone Concrete

The concrete cover-zone is a major factor governing the degradation of concrete structures as it provides the only barrier to aggressive agents which initiate corrosion of the reinforcement. Knowledge of the protective qualities of cover-zone concrete is critical in attempting to make predictions as to the in-service performance of the structure with regard to likely deterioration rates for a particular exposure condition and compliance with specified design life. To this end, a multi-electrode array was used to study the surface 50mm of concrete specimens thereby allowing a detailed picture of the response of the covercrete to the changing environment. In the current work, CEM I, CEM II/B-V and CEM III/A cements were used and comprised field studies representing a range of exposure conditions.