CONTROL OF REINFORCEMENT CORROSION BY SURFACE TREATMENT OF CONCRETE

It is known from laboratory studies that reinforcement corrosion in carbonated concrete can be controlled simply by ensuring that the concrete remains relatively dry. An apparently obvious and cost effective way of excluding external moisture from building components which are not exposed to effects of capillary suction from groundwater, etc. is by applying a waterproof coating to the surface of the concrete. A research programme was undertaken for six years, with the primary aim of assessing whether coatings with appropriate characteristics could maintain suitably dry conditions within concrete in real carbonated structures. A secondary aim was to determine whether a similar predicted extension of the service life could be achieved if corrosion of the reinforcement were induced by internal chlorides. It was recognized from the outset that trials on real structures should be planned so that critical questions that determine the feasibility of the protection technique might be answered. This paper gives an...