Abstract
In the manufacture of soil-cement concrete using cement, soil and sand, precise control of the amount of water which assure the designed strength must be based on a consistent relationship of strength-water cement ratio supported by the concept of the effective water. We developed a new testing method, the drying acceleration method, that can estimate the saturated surface-dry state of soils, which forms the base of the concept of the effective water. Sample soils were taken from ten different construction sites over Japan, and four type of sand and one kaolin were used. Apparent saturated surface-dry state of these sample soils and sands were defined by this method. Our findings can be summarized as follows,
(1) The apparent saturated surface?dry state do exist for soils.
(2) The apparent saturated surface?dry state can be determined by the drying acceleration method.
(3) The drying acceleration method may be favorably executed when the size of soil specimen is 5 mm under a drying condition of temperature at 40°C and relative humidity of 40% with an interval of measurement 60 minutes for soils and 10 minutes for sands.
