Compression Behavior of Secondary Clay Minerals at High Initial Water Contents

Abstract

This study shows the influence of initial water content on the compression behavior of secondary clay minerals: kaolin, illite, and montmorillonite. Oedometer tests were carried out on these minerals with different initial water contents which are ranging from one to two times their corresponding liquid limits. The findings show that the initial water contents can result in different compression behaviors of secondary clay minerals. The compression indices of secondary clay minerals, and , increase nonlinearly with increasing initial water contents, and compression behaviors among samples become insignificant gradually. Meanwhile, it is also noticed that the effect of initial water content on of montmorillonite is smaller than that of kaolin and illite. However, the effect of initial water contents on of secondary clay minerals is close. Due to the remolded yield stresses existing in remold soils, all the e∼logσ′ compression curves of the three secondary clay minerals present an inverse ‘S’ shape. The initial water contents have different effects on remolded yield stress of secondary clay minerals. It has most significant effect on illite, and less effect on kaolin and montmorillonite.