Determination of saturated surface-dry condition of clay-sand mixed soils for soil-cement concrete construction

摘要

Saturated surface-dry condition of soil needs to be known when soil-cement concrete mix is rationally designed. Based on the effective water concept, determination of the saturated surface-dry moisture content (hereafter referred to as w_(ssd)) of clay-sand mixed soil, necessary for determining unit water of soil-cement concrete construction, is dealt with in this study. The saturated surface-dry condition of soil, where soil water exhibits the same chemical potential as that of cement paste, can be determined both with drying rate method and pF method. Mixed soils were prepared in combination with six cohesive soils, standard sand and a recycled fine aggregate. Drying rate method and pF method were proven to be effective in determining w_(ssd) of any combinations of the soils. Relationship between volume fractions of cohesive soil and sand and w_(ssd) was found to be a linear equation.