A Study on Prediction Method of Time-Dependent-Change of Flowability for Highly Flowable Mortar
Tomoji KUMANO, Kiyoshi YAMURA and Kenji NAKURA
Abstract:Time-dependent-change of flowability of fresh concrete is very important for developping concrete practice design method. In this study, as the first step of establishing a method for predicting the change, time-depending-change test of highly flowable mortar was carried out. The main factors of this experiment were dosage of superprasticizer and temperature of mortar. The test showed that rheological constants becomes larger with time for less dosage of superprasticizer and higher temperature of mortar. A prediction model of time-dependent-change of viscosity for highly flowable mortar was investigated referencing Hattori-Izumi theory. The stability ratio of the theory was estimated using the experimental results. The ratio varies with dosage of superplasticizer and temperature of mortar. It is concluded that the prediction model can be developed when the variation of the stability ratio is fully understood. Key Words:Time-depending-change, Highly flowable mortar, Rheological constants, Stability ratio, Potential energy