Experimental study on strength and microstructure of loess reinforced with F1 ionic soil stabilizer

In order to study the physical and mechanical properties of loess reinforced with F1 ion curing agent, California bearing ratio (CBR) test, unconfined compressive strength test and triaxial unconsolidated undrained test were carried out. Based on the results of scanning electron microscope (SEM), nuclear magnetic resonance (NMR) and X-ray diffraction (XRD), the mechanical properties and micro-pore structure of loess reinforced by F1 ion curing agent were studied. The test results show that the F1 curing agent can reduce the plastic limit, increase the liquid limit, plastic index and maximum dry density of soil by cation exchange, destroy the double layer structure and the hydrophobic effect of sulfonated oil, and improve the water sensitivity and compaction characteristics of soil; F1 can significantly increase the CBR value, unconfined compressive strength and shear strength parameters, and 0.3 L/m3 is the best dosage of loess reinforcement; F1 changes the pore structure and contact form between particles, promotes the aggregation and condensation between particles, reduces the fractal dimension of the pore distribution of microstructures from 1.244 to 1.076, and greatly reduces the total pore area and total pore number of soil. Under the action of rolling, a laminated stack structure with tighter arrangements, larger agglomerates and surface-to-face contact is formed as main contact style, which enhances the compactness and bearing capacity of the soil. © 2021, Editorial Department of Journal of Southeast University. All right reserved.