Study on the Mechanical Properties of Loess Improved by Lignosulfonate and Its Mechanism Analysis and Prospects

As an organic material with large reserves and environmental protection, the application of lignin in loess improvement can greatly improve the engineering properties of loess, such as water loss disintegration and water collapsibility. This paper summarizes the main achievements of lignosulfonate in improving loess over the past five years and discusses and analyzes its microstructure, mechanical properties, and mechanism of action. The microscopic results show that the incorporation of lignosulfonate produces a three-dimensional network structure, which can effectively cement loess particles and improve soil strength and impermeability, and the Quantity of this network structure depends on the amount of lignosulfonate. An excessive amount of lignosulfonate preferentially combines with itself due to its cohesive and chelating properties, resulting in an increase in soil porosity and a decrease in the improvement effect. Based on the macroscopic and microscopic tests, it was concluded that the optimal dosage reference range of lignosulfonate-improved loess is mostly between 1% and 1.5%. However, considering the limited number of references in this paper, the differences in physical properties of the experimental loess used in the literature, and the different curing ages, the optimal dosage needs to be further studied. The discussion and analysis in this paper provide a reference for research on lignosulfonate-improved soil, as well as new knowledge and information for more efficient engineering applications of lignin-improved loess.