In concrete technology terms curing of concrete is considered an integral part of the overall construction process in order to achieve its full in-situ performance and durability. However, it is still seen by many as an unnecessary impediment to further work and the ability to move on as soon as possible to the next stage of the work. Even when some effort is made to satisfy specification requirements, this is sometimes done in a half-hearted manner and often associated with poor practice. The purpose of this paper is to present relevant research work which demonstrates the fundamental importance of curing of concrete in achieving desired properties such as low penetrability (i.e. low VPV - volume of permeable voids), design strength, stripping times, serviceability and, very importantly, durability. The data presented shows that continuous and uninterrupted moist curing under controlled conditions is by far the most effective curing technique. However, the investigation also established that curing compounds and to a lesser extent polyethylene plastic sheeting (by itself) can have an adverse effect on both strength development and VPV of the concrete. The paper finally summarises the performance of the various curing methods and presents a series of recommendations in relation to their usage. The effects of curing on the optimum development of the concrete microstructure and the desirable conditions required for an effective curing process are also discussed. (a)
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