Correlation analyses of effects of temperature on physical and mechanical properties of clay

In determining the physical and mechanical parameters of clay, it is sometimes necessary to determine them indirectly from other parameters since they cannot be measured directly from laboratory or field tests. In order to determine the effect of temperature on the behavior of clay, an indirect approach is used here by analyzing the changes of mass ($\Delta m$), density ($\rho$), porosity ($\varphi$), P-wave velocity ($v_p$), thermal conductivity ($\lambda$), specific heat capacity (c), resistivity (R) and uniaxial compressive strength (f) of clay from eastern China for a temperature range between 20 and 800 °C. The results indicate that temperature has a significant effect on these parameters. Comparisons between $\Delta m$ and $\rho$, $\Delta m$ and $v_p$, $\rho$ and $v_p$, $\varphi$ and $\lambda$, $v_p$ and f, R and f show a linear change among these parameters,whereas the relationships among $\Delta m$ and $\varphi$, $\varphi$ and $v_p$, $\varphi$ and R, $v_p$ and $\lambda$, $\varphi$ and f are exponential. It is difficult to obtain these relationships by using regression analysis with high levels of accuracy. Further refinement is therefore required.