Abstract
The objective of this research is to propose the method for estimating the water retaining factor and the flowing factor, which are properties of powder concerning paste flow, with particle size distribution, particle shape and property of hydration of cement. The results obtained are as follows: The water retaining factor is proportional to the product of the index represent particle size and the index represent form of particle size distribution, and its proportionality constant represent particle shape and property of hydration. The flowing factor is proportional to the product of the index represent particle size and the index represent particle shape and property of hydration, and the constant term represent surface condition of powder supposing its proportionality constant is fixed.
