Trrl Lr 953

It is shown that in order to monitor corrosion in a system as complex as reinforced concrete it is necessary to utilise a combination of methods giving different types of corrosion information in order to achieve a reliable assessment of the extent of corrosion over the structure. A comparatively high number of measurements per unit area of concrete surface are essential since the concrete is never uniform and localised corrosion is common. The techniques which justify a high measurement density are identified. The relative importance of these methods is indicated for some frequently occuring practical conditions. It is anticipated that this report will provide sufficent information to enable the engineer to make a constructive choice of test methods so that a reasonably accurate assessment of which areas of reinforcement are corroding can be established.