"Property of p-1, 3-Glucan (Curdlan) as a Viscosity Agent for Super-Workable Concrete"

A super workable concrete is defined as the concrete which has excellent deformability, high resistance to segregation, and can be filled into heavily reinforced areas without applying vibration. High deformability and high resistance to segregation are important properties of super workable concrete. Since these properties are essentially opposite in nature, they have a tendency to be sensitive to quality fluctuations of materials in comparison to conventional concrete when manufactured at ready mixed concrete plants. For improvement of manufacturing and handling, the authors developed the super workable concrete using B-1, 3-Glucan (Curdlan) which is produced by a fermentation process as a viscosity agent. The purpose of this study is to investigate the properties of B-1, 3-Glucan which gives a super workable concrete and the mechanism by which it produces such effects. The results confirm that B-1, 3-Glucan exists in the form of independent swollen particles, calcium complex gel which have negative electric charge on their surface. They also indicate that B-1, 3-Glucan has the ability to increase the viscosity of cement slurry. Thus, B-1, 3-Glucan gives and effect to increase plastic viscosity without changing yield value of a mortar, which was obtained by wet-screening a concrete.