One-dimensional compressibility of soft clay related to clay minerals

In order to investigate the influence of minerals on the compressibility of clay, the artificial mixtures with different weight proportions of clay minerals (i.e., kaolinite, illite, montmorillonite and chlorite) are prepared. The conventional oedometer tests are carried out on these remolded soil samples. Comparisons among the experimental results indicate that (1) for mixtures of kaolinite and illite, the compression index and rebound index increase with the increase of the content of illite; (2) for mixtures of kaolinite, illite and montmorillonite, they increase with the content of montmorillonite; and (3) for mixtures of kaolinite, illite, montmorillonite and chlorite, they increase with the content of montmorillonite and chlorite, and the montmorillonite has the dominant contribution. Based on the experimental results, two nonlinear equations are proposed for both the compression and rebound indices considering the influence of clay minerals. In addition, it is found that the value of C_c/C_s for all mixtures varies from 6.1 to 9.1.