Abstract:Based on the different contents of calcium lignosulfonate and curing ages, the water repellency, permeability, and water stability of calcium lignosulfonate were analyzed using the water drop infiltration, penetration, and disintegration tests, respectively, to reveal the influence of calcium lignosulfonate on the hydrological properties of Lanzhou loess. The improvement mechanism of enhanced loess by calcium lignosulfonate is also discussed using X-ray diffraction and scanning electron microscope tests. Results show that the water repellency and stability of loess improved with the addition of calcium lignosulfonate. Moreover, the improvement of calcium lignosulfonate with low content is limited, while the overall performance of loess improved by high-content calcium lignosulfonate is good. However, the effect of reducing permeability is limited. The hydraulic properties of loess improved by calcium lignosulfonate demonstrate age effects: under the curing age of 28 d, a generalized peak value is observed in the hydraulic property parameters of loess improved by calcium lignosulfonate with its content. However, the relationship between peak value and content is different. A certain positive correlation is also observed between the hydraulic and mechanical properties of loess improved by calcium lignosulfonate. No new mineral composition is found in the loess improved by calcium lignosulfonate. However, the thickness of the electric double layer of soil particles becomes thin, and the cementing products wrap the connecting particles and fill the pores, thus improving the hydraulic properties of the loess.
