On the Compressibility of Cement Stabilized Zinc-Contaminated Kaolin Clay

Abstract

In this study, a one-dimensional compression test was conducted to investigate the effect of zinc concentration on the compressibility of cement-solidified, zinc-contaminated kaolin clay. Post-yield compression index (Cc) and yield stress (ovy') of stabilized soils were obtained and correlated with initial zinc concentrations. It was found that zinc concentration significantly affected the compressibility of stabilized kaolin clay in terms of Cc and ovy'. Cc decreased marginally and sharply when zinc concentration ≤ 0.1% and > 0.1%, respectively. Yield stress decreased steadily with increased zinc concentration. To quantify the influence of zinc concentration on the cementation structure/bonding and, further, the compression characteristics of the cement-stabilized kaolin clay, the concepts of void index (Iv), Intrinsic Compression Line (ICL) and Sedimentation Compression Line (SCL) were used to analyze the compression test data. The locations of compression lines of the stabilized kaolin relative to those of ICL and SCL, were discussed. The convergence of compression lines of stabilized kaolin with ICL was analyzed as well. The results reveal that as zinc concentration increases, cement stabilized kaolin clay exhibits weakened cementation structure/bonding. It is demonstrated that zinc has a considerably destructive effect on the cementation structure/bonding, which in turn affects the compression characteristics of the cement-stabilized, zinc-contaminated kaolin clay.