セメント安定処理土のアルカリ溶出特性とその制御

Abstract

A large number of surplus soils are generated from construction works and most of them are only disposed of in waste disposal sites. In order to promote effective use of the surplus soils, it is required to improve their properties by cement and/or lime stabilization.However, as cement or lime stabilized soils exhibit the high value of pH, the environmental impact of the alkaline solution must be carefully concerned.The objective of this study is to discuss the method or concept to control the environmental impact induced by the use of cement stabilized soil. The alkaline leachate characteristics from the stabilized soils, the buffer ability of cover layer and the interaction of these functions were investigated through the experimental studies; alluvial clay and decomposed granite were used in this study and a series of permeability and pH test were carried out on compound specimens of stabilized soil and buffer layer. Based on the experimental results, the minimum thickness of cover layer of the stabilized-soil embankment was estimated through the parametric study. It is concluded that the buffer ability of cover soil and the permeability of both stabilized soils and cover layer are important to control the environmental impact by alkaline leachate.