Evaluation method for consistencies of mortars with various mixture proportions

Abstract

Mortar and concrete are composed of solid materials and water, so that all the solid material particles can be considered to be coated with an "excess water film." In this study, the functions of this excess water film were investigated through mortar tests and solid volume percentage tests of the solid materials in mortars. It was found that the consistency of fresh mortars such as mini-slump and flow can be evaluated by the ratio of the average thickness of the excess water film to the surface-volume average diameter of the particles of cement and fine aggregate, even for various mortar mixture proportions and fine aggregate gradings. This ratio was also found to be a reliable index to determine the optimum replacement percentage when a part of the fine aggregate in mortar is to be replaced with a mineral admixture. Copyright © 2007 Japan Concrete Institute.