Effect of superplasticizers on the plastic shrinkage of concrete

Abstract

This Paper presents the results of a study on the effect of five different superplasticizers on plastic shrinkage of concrete. Test specimens of fresh concrete were subjected to a simulated hot dry environmental condition of 35°C, 50% RH and a wind velocity of 3·5mls immediately after casting. Measurements were made of surface tension, bleeding rate and negative capillary porewater pressure. It was found that the time of occurrence of an initial peak or plateau of capillary porewater pressure is related to surface tension and the development of plastic shrinkage.