Title: Evaluation of Autogenous Deformation of Concrete at Early Ages
Author(s): Sam Slatnick, Kyle A. Riding, Kevin J. Folliard, Maria C. G. Juenger, and Anton K. Schindler
Publication: Materials Journal
Appears on pages(s): 21-28
Keywords: autogenous shrinkage; internal curing; lightweight aggregate; self-desiccation; shrinkage-compensating concrete; shrinkage-reducing admixtures
Autogenous shrinkage, significant primarily in concretes with a low water-cementitious material ratio (w/cm), has received more attention in recent years due to the increasing use of high-performance concretes (HPCs). In this study, autogenous shrinkage was quantified in both unrestrained and restrained concrete. The specimens were sealed and kept at a constant isothermal temperature of 20°C (68°F) to prevent deformation due to temperature change or moisture loss. Various materials were evaluated to compare their effectiveness in reducing autogenous deformation and stress development, including saturated lightweight aggregates, shrinkage-reducing admixtures (SRAs), and a shrinkage-compensating additive (based on calcium sulfoaluminate). The data obtained also provide insight into the mechanisms behind autogenous shrinkage and the resulting stress development in restrained members and quantify the effects of methods used to reduce autogenous shrinkage and the resultant stresses.