1996 年 45 巻 9 号 p. 979-984
The fluidity of highly-flowing concrete is influenced by the fluidity of composed mortar. This paper discusses the rheological-estimation of the fluidity of highly-flowing mortars. It is considered that the characteristic of fine aggregate is the most influential factor for fluidity of mortar. The viscosity equation proposed by Mori and Ototake for the condensed suspension liquids was examined first for its application to highly-flowing mortar. Mortars with different volume concentrations of fine aggregate suspended in highly-flowing paste were tested. The results of the rheological tests a Brookfield type viscometer indicated good applicability of the equation. Provided that the fluidity of mortar behaves as a Bingham fluid, it can be estimated by the plastic viscosity and yield value.
The tests were also made on two types of highly-flowing mortar used for highly-flowing concrete with 60-70cm of slumping flow value. The effect of fine aggregate varied with water content, sand content and sand grading. The test results showed that the character of sand remarkably affects the fluidity of highly-flowing mortar.