Testing Methods for Water Absorption and Saturated Surface-Dry Condition of Mixtures of Cohesive Soil and Sand

Testing methods for saturated surface-dry condition of the cohesive soil and sand mixture which is necessary for determine the amount of water based on the concept of effective water content in the manufacture of soil cement concrete are presented. The authors have proposed four methods in the previous papers1), 2) capable of determining the apparent saturated surface-dry condition of soil by means of the drying acceleration, silica gel, relative permittivity and pF method. In this paper, it is confirmed that the saturated surface-dry condition of mixtures of 6 types of cohesive soil, a river sand and a recycled fine aggregate with variable grain composition and moisture content can also be determined by both drying acceleration method and pF method. A relation between water absorption of the mixture and mixing ratio of cohesive soil and sand has been derived in a simple formula.