Integrative Studies on Autogenous and Drying Shrinkages of Concrete at Early-Age

Abstract

In order to study the relationship between shrinkage strain and interior humidity, experimental measurements on shrinkage and interior humidity of early-age concrete under both plastic sealing and drying conditions were carried out. The experimental results show that the development of shrinkage and the interior humidity are of high relativity. The drying process increases the shrinkage strain. Meanwhile, this process also leads a fast reduction on the interior humidity. Based on the experimental findings, a theoretical model for shrinkage prediction of concrete at early-age is developed. The model relies on the interior factors, chemical shrinkage and internal humidity, which may relate to the moisture loss in concrete directly. Therefore, the model can be used for shrinkage prediction of concrete, whatever the shrinkage is caused by self-desiccation or by dying. The model predictions are compared with experimental results and a reasonable agreement between them is found.