Reference:  D.P. Bentz, to be submitted to Concrete International (2005).

Potential Applications of Shrinkage-Reducing Admixtures beyond Drying Shrinkage Reduction

Dale P. Bentz
Building and Fire Research Laboratory
National Institute of Standards and Technology
100 Bureau Drive Stop 8615
Gaithersburg, MD 20899-8615 USA

E-mail: dale.bentz@nist.gov

Abstract

Currently, shrinkage-reducing admixtures (SRAs) are marketed by numerous chemical admixture companies for reducing drying shrinkage (and its associated cracking) in concrete. Most SRAs function by reducing the surface tension of the pore solution in the concrete. In addition to reducing or slowing drying shrinkage, this reduction in surface tension can also potentially reduce autogenous shrinkage in low water-binder ratio mortars and concretes and evaporative water loss during early age curing. In this paper, a consistent theoretical basis for these reductions will be presented. In addition, example results illustrating the usage of solutions of shrinkage-reducing admixtures as a potential curing solution will be contrasted against those obtained using only water.

Keywords: autogenous shrinkage; building technology; curing; drying shrinkage; evaporation; shrinkage-reducing admixture; surface tension.

• Introduction
• Theoretical Background
• Experimental
• Results and Discussion
• Conclusions
• Acknowledgements
• References