Abstract: Based on the study of emulsified asphalt (AE) composite stabilized silt, we prepared an FG curing agent using inorganic/organic composite materials for the silty soil near the Yellow River in Qihe county. We compared the strength properties, moisture stability and frost resistance between AE-stabilized and FG-stabilized silty soils, and furthermore discussed the stabilizing mechanism of FG curing agent via XRD and SEM. Our findings demonstrated that the silty soil stabilized by FG curing agent had better moisture stability and higher unconfined compressive strength, resilient modulus, bearing capacity, and frost resistance than AE-stabilized soil. XRD and SEM analysis suggest that the composite cementation effect and filling enhancement of the active minerals provided by the FG curing agent guaranteed the strength of the stabilized soil; the polymer material played the role of binding the particle interface and filling the pores, reducing the internal void ratio; and both boosted the maximum dry density of the soil; FG-stabilized soil displayed a different stability mechanism from that of AE-stabilized silt. The use of FG curing agent provides a reference for the stability and engineering application of Yellow River silty soil.

Key words: Yellow River silty soil, composite stabilization, unconfined compressive strength, frost resistance, moisture stability