Curing effect in the shrinkage of a lower strength self-compacting concrete

Self-compacting concrete possesses special properties that recommend its application in many repair jobs. However, in some practical cases, inappropriate performance of the repair material has been observed in the early stages of hydration, including cracks or delamination due to shrinkage. As the use of self-compacting concrete becomes more prevalent, some novel techniques to combat this phenomenon have been developed, but control of curing conditions continues to be an important prerequisite. In this study, experimental work on the curing effect on the total shrinkage of a lower strength self-compacting concrete, is presented. The curing effect was evaluated on compositions made with different commercial shrinkage-compensating products. The results obtained indicate that all the compositions (with or without shrinkage reducing admixtures and expansive product) have a higher long-term total shrinkage when subject to cure. It was found that the specimens subject to a longer curing period have lower median pore diameter. The higher total shrinkage was related to the refinement of structural porosity. The results also confirm that the curing time is essential to minimise the shrinkage at early ages. It causes a lower drying mass loss causing a delaying effect in the development of shrinkage allowing the natural strength development. (C) 2015 Elsevier Ltd. All rights reserved.