Thermo-hydro-mechanical behaviour of Malaysian kaolin under one-dimensional conditions

This experimental research examines the mechanical response of Malaysian kaolin under one- dimensional compression at different levels of matric suction and temperature. The laboratory program focuses on assessing the thermal effects separately from the suction effects by considering three kinds of tests: suction-monotonic, temperature-monotonic, and thermal-cycling tests. Four suction levels are evaluated on the suction-monotonic tests, i.e., 0, 500, 1000, and 1500 kPa through the axis-translation technique. Besides, four temperature levels are employed on the temperature-monotonic tests, i.e., 20, 50, 70, and 90 °C. In addition, a thermal cycling test involving 100 cycles of temperature variation between 30 °C and 50 °C is performed to study the mechanical response under repeated thermal loading. The main findings from this investigation are as follows: (i) the kaolin is stiffer at more elevated suction levels; (ii) at more elevated levels of suction (i.e., 1000 and 1500 kPa), the mechanical behaviour of the kaolin is practically equal; (iii) the compressibility of the kaolin augments as the temperature increases; and (iv) the kaolin exhibits progressive changes in axial stress under thermal cycles, with peak axial stresses at peak temperature (i.e., 50 °C) and valley stresses at valley temperature (i.e., 30 °C).