Coupling effect of landfill leachate and temperature on the microstructure of stabilized clay

This paper studies the microstructure of stabilized clay polluted by landfill leachate at different temperatures. For this purpose, dynamic corrosion-stabilized clay was used to prepare mercury intrusion porosimetry and scanning electron microscopy samples by lyophilization. The results showed that a rise in temperature affects the pore structure of corrosion-stabilized clay. Macropores are easily produced when the temperature ranges from 40 to 60 °C, while cryptopores and ultramicropores appear in significant numbers if the temperature reaches 80 °C. The corresponding micrographs show a dispersed structure at temperatures of 40 to 60 °C and a clearly flower-like structure at 80 °C. Landfill leachate has obvious effects on the microstructure of stabilized clay. After corrosion processes, pore size is reduced while average pore radius is increased. Macropores increase and span a wider range. The peak of the pore size distribution curve shifts from the middle to both ends; porosity initially decreases and then increases. From the chemical point of view, this corrosion mechanism is mainly due to the growth of new material such as calcium chloro-aluminates, ettringite or dihydrate gypsum that were generated by the reaction between landfill leachate and stabilized clay.