Basic Study on the New Testing Method of Judging the Saturated Surface Dry Conditions of Fine Aggregates

This paper describes a basic study on the development of a new method to judge the saturated surface-dry condition of fine aggregates. The new method is based on the idea that the electric resistance of a sample depends on the moisture content of the sample. The relationship of the electric resistance with the moisture content of a sample is directly and radically changed by the existence of water on the surfaces of the particles. This becomes clearer when an electrolyte is added to the sample. The relationships between the electric resistance and the moisture content of a sample were investigated for various types of fine aggregates when an electrolyte was added. This relationship shows radical changes in the electric resistance near the saturated surface-dry condition. The chemical compositions of a sample do not influence the relationship of the electric resistance with the total moisture content of the sample. The applicability of the electric resistance test will be confirmed if the data of specimens with various physical properties will be investigated statistically.