新しい土の見掛けの表乾状態判定試験方法の提案

Abstract

This paper deals with the evaluation method of the apparent saturated-surface dry state of soil necessary for the precise control of strength on the basis of water-cement ratio. The newly proposed methods by the authors are the drying acceleration method, the silica gels sprinkling method, the relative dielectric constant method and the pF method.A detailed description of the drying acceleration method was presented in the previous paper, and the test samples, four types of sand, ten types of soil and a kaolin, were used as in the previous study. The major findings on this study are as follows.(1) The moisture content of the apparent.saturated-surface dry state of soil obtained from the singular point which can be found each moisture content-index relation of either the drying acceleration method, the silica gels sprinkling method and the relative dielectric constant method showed fairly. good agreement with each other, and the moisture content fall into that of pF.5.1-5.3 of pF-moisture content relation curves.(2) The moisture content of the apparent saturated-surface dry state of soil evaluated by four different methods coincide with each other without regards to the type of soil where by the silica gels. sprinkling method, the relative dielectric constant method and the pF method can be used for assessing the apparent.saturated-surface dry state of soil in addition to the drying acceleration method.(3) The silica gels sprinkling method can be used as a rapid test whereas the drying acceleration method should be the standard method. The relative dielectric constant method and the pF method require some special apparatus.