Experimental Study on the Curing Mechanism of Red Mud-Based Stabilized Soil Co-Modified by Nano-SiO2 and Gypsum

Abstract

In order to effectively utilize red mud and reduce its occupation of land resources, as well as its impact on the environment, experiments were conducted to develop stabilized soil materials using nano-SiO2 synergistically modified red mud and to investigate the curing mechanism of stabilized soil. The unconfined compressive strength, microscopic morphology, and curing mechanism of the red mud-based stabilized soil materials with different amounts of modified materials were investigated. The test results show that after 7 days of curing, the unconfined compressive strength of red mud-based stabilized soil meets the compressive strength requirement of road base material when nano-SiO2, gypsum, and cement are synergistically modified. In such cases, the soil structure has the lowest fracture rate and the best structural compactness when the amount of nano-SiO2 is 1%. It is found that the needle-like and columnar calcium alumina in the modified red mud-based stabilized soil increases, and the binding energy of hydration product ions in the modified material is improved. The chemical curing mechanism of modified red mud-based stabilized soil includes hydration reaction, pozzolanic reaction, promotion effect of nano-SiO2, and enhancement effect of gypsum. On this base, a model of the early start hydration process of red mud-based stabilized soil promoted by nano-SiO2 is established.

Special Issue “Construction Materials and Other Related Materials: Basic Theory, Applied Technology and Advanced Research Methods”

“…The research conducted by Chen et al [ 3 ] emphasizes the efficacy of synergistically enhancing red mud-based stabilized soil by incorporating nano-SiO 2 and gypsum. Subjecting the soil to a 7-day curing process demonstrates satisfactory compressive strength characteristics, fulfilling the prescribed standards for road subgrade materials.…”

“…Drawing upon the fundamental principles of mechanics, this approach continually incorporates the most recent research discoveries from mechanics and related fields, enhancing the disciplinary knowledge reservoir and adeptly tackling engineering challenges. This Issue encompasses theoretical and applied research contributions, with a particular emphasis on fostering collaboration across other disciplines [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…A classification scheme was created based on the themes and areas of attention of the study publications. The 15 papers in this Special Issue were divided into four general categories: Multi-Phase Materials and Enhancers, which investigated the analysis and evaluation of mechanical properties and performance enhancement methods for various materials [ 2 , 3 , 5 , 9 ]; Geotechnical Mechanics and Soil Engineering, which examined topics like rock mechanics, swelling pressure–suction relationship, grout properties, and excavation-induced ground response [ 1 , 6 , 7 , 14 ]; Concrete Mechanics and Materials, which concentrated on the effects of organic matter components, constitutive relationships, and concrete strength [ 4 , 8 , 15 ]; (Hydro-mechanics, Groundwater, and Slope Stability, involving the study of the time-dependent effect of seepage force on hydraulic fracture initiation and the failure mechanism of slopes during heavy rainfall events [ 11 , 12 , 13 ]. …”

“…Multi-Phase Materials and Enhancers, which investigated the analysis and evaluation of mechanical properties and performance enhancement methods for various materials [ 2 , 3 , 5 , 9 ];…”