Abstract: Silicifrcation is one of the chemical methods of collapsible loess treatment. For better silicification effect, sodium silicate is modified by various methods. The mechanism of loess reinforced by temperature modified sodium silicate is studied. The physical component such as chemical composition and mineral composition, microstructure are tested and analyzed by carrying out X-ray diffraction (XRD), scanning electron microscope(SEM) and mercury intrusion porosimetry (MIP). The results show that the mechanical strength of loess is improved obviously with the temperature of sodium silicate increasing in the temperature range of 20~80℃. Diffraction intensity of parts of the mineral is reducing in the X-ray diffraction patterns; and low density amorphous phase peak groups appeared. The SEM images show that the gel films increased with the temperature of sodium silicate increasing. MIP data show that surface area of pores increased with the temperature increasing. The findings indicate that the increased amorphous phase and the gel films caused to decreased most probable pore size and increased small pores. The mechanism of loess reinforced by temperature modified sodium silicate is due to reinforcement of the bond strength of cement in microstructure and formation of three-dimensional networks of frame.

Key words: modified sodium silicate, temperature, loess, compressive strength, microstructure, chemical analysis