Study of the Behavior of Concrete with shrinkage Reducing Admixtures Subjected to Long-Term Drying

Shrinkage is an important consideration in structural design for serviceability and crack width limits. The ability to design concretes with significantly lower shrinkage is, therefore, of great practical importance. This paper analyzes some of the new shrinkage reducing admixtures (SRA) that have been developed to reduce the extent of shrinkage strains. Specifically, the unrestrained or free shrinkage deformation of concrete incorporating two SRAs based on polypropylene glycol formulations are evaluated over a drying period of seven months. Additionally, the effectiveness of a product based on a wax formulation is studied. Companion tests on two base concretes without SRA have also been performed.