Experimental investigation of coupled thermo-mechanical behaviour of Kaolin clay

An experimental study regarding the thermo-mechanical behaviour of a Malaysian Kaolin is presented in this paper. Mercury intrusion porosimetry (MIP) tests have been performed on compacted samples with varying initial water contents. Samples compacted at dry side of optimum showed a bi-modal pore size distribution (PSD), while samples compacted at optimum or wet side of optimum showed a mono- modal PSD. The potential of the soil for thermal collapse was evaluated using the data of the MIP tests. It was concluded that soils with a bi-modal PSD (dry of optimum) have the potential for thermal collapse while soils with a mono-modal PSD (optimum/wet of optimum) usually show a dilative behaviour. This dilative behaviour was later confirmed using the data obtained from heating saturated, highly OC samples to a desired temperature. By performing temperature controlled oedometer tests in the range of T = 20°C to T = 90°C on saturated samples it was shown that the apparent preconsolidation pressure decreases with increasing temperature. Furthermore, the influence of temperature on the compressibility was evaluated suggesting that temperature has no influence on the compression index and the swelling index while the recompression index decreases with increasing temperature.