Soil stabilizers are environmentally friendly engineering materials that enable efficient utilization of local soil-water resources. The application of nano-modified stabilizers to reinforce loess can effectively enhance the microscopic interfacial structure and improve the macroscopic mechanical properties of soil. This study employed nano-SiO2 and nano-CaCO3 to modify cement-based soil stabilizers, investigating the enhancement mechanisms of nanomaterials on stabilizer performance through compressive and flexural strength tests combined with microscopic analyses, including SEM, XRD, and FT-IR. The key findings are as follows: (1) Comparative analysis of mortar specimen strength under identical conditions revealed that nano-SiO2 generally demonstrated superior mechanical enhancement compared to nano-CaCO3 across various curing ages (1-3% dosage). At 1% dosage, the compressive strength of both modified stabilizers increased with curing duration. Early-stage strength differences (3 days) remained below 3% but showed a significant divergence with prolonged curing: nano-SiO2 groups exhibited 10.3%, 11.3%, and 7.2% higher compressive strengths than nano-CaCO3 at 7, 14, and 28 days, respectively. (2) The strength enhancement effect of nano-SiO2 on MBER soil stabilizer followed a parabolic trend within 1-3% dosage range, peaking at 2.5% with over 15% strength improvement. (3) The exceptional performance of nano-SiO2 originates from its high reactivity and ultrafine particle characteristics, which induce nano-catalytic hydration effects and demonstrate strong pozzolanic activity. These properties accelerate hydration processes while promoting the formation of interlocking C-S-H gels and hexagonal prismatic AFt crystals, ultimately creating a robust three-dimensional network that optimizes interfacial structure and significantly enhances strength characteristics across curing periods. These findings provide scientific support for the performance optimization of soil stabilizers and their sustainable applications in eco-construction practices.

The composite rapid soil stabilizer (CRSS) is a newly developed material for rapid curing of sludge with fast setting, fast hardening, and high strength properties. CRSS was used to solidify the sludge, and the durability test of the solidified sludge under the action of sulfate erosion was carried out to analyze the influence of erosion time and Na2SO4 and MgSO4 concentration on the physical and mechanical properties of the solidified sludge. The research results showed that as the erosion time increased, the mass of soaked samples increased gradually. Additionally, the strength of samples soaked in clear water continued to rise, while the strength of samples soaked in sulfate increased first and then decreased. After 112 days of erosion, the higher the concentration of SO42-, the greater the mass of the soaked sample and the lower the strength. At the same concentration, the mass of the soaked sample with MgSO4 was the largest, but the strength was the lowest. Under the action of sulfate attack, the soaked samples produced a large number of expansive products, and the cumulative pore volume first decreased and then increased. The microstructure of the MgSO4-soaked samples suffered the most damage due to the double corrosion of Mg2+ and SO42-. Based on the macroscopic and microscopic test results, the microscopic evolution mechanism of the durability of solidified sludge under Na2SO4 and MgSO4 erosion environments was revealed. The solidified sludge with CRSS has good sulfate resistance durability, which lays a theoretical foundation for the engineering application of CRSS.

The traditional cement-based stabilization cannot effectively stabilize the marine soft clay under submerged conditions. In order to solve this problem, the enhancement of cement-stabilized marine soft clay was investigated in this study by adding the ionic soil stabilizer (ISS) and polyacrylamide (PAM). For this purpose, varying contents of ISS and PAM (ISS-P) were added into cement-stabilized marine soft clay and subjected to curing under submerged conditions. Atterberg limits tests, direct shear tests, unconfined compression strength (UCS) tests, water-stability tests, scanning electron microscopy analysis, and X-ray diffraction analysis were carried out. The results show that using 1.8% ISS and 0.9% PAM as the optimal ratio, the cohesion, internal friction angle, UCS, and water-stability of the samples increased by 182.7%, 15.4%, 176.5%, and 368.5% compared to the cement-stabilized soft clay after 28 d. The increment in soil cohesion with increasing ISS-P content was more apparent than that in the internal friction angle. The combined action of ion exchange attraction and electrostatic adsorption altered the failure characteristics of the samples, resulting in localized micro-cracking and multiple failure paths. Increasing the content of ISS-P strengthened the skeletal structure of soil, reduced inter-particle spacing, and enhanced the water-stability. Additionally, ISS promotes the hydration of cement and compensates for the inhibitory effect of PAM on early cement hydration. ISS-P can effectively enhance the strength and stability of submerged cement-based stabilized marine soft clay.

The ionic soil stabilizer (ISS) can synergistically enhance the mechanical properties and improve the engineering characteristics of iron tailings soil in conjunction with cementitious materials such as cement. In this paper, the influence of ISS on the cement hydration process and the charge repulsion between iron tailings soil particles was studied. By means of Isothermal calorimetry, X-ray diffraction (XRD), Scanning electron microscope (SEM), and Low-field nuclear magnetic resonance microscopic analysis methods such as (LF-NMR), X-ray photoelectron spectroscopy (XPS), Non-evaporable water content and Zeta potential were used to clarify the mechanism of ISS-enhanced cement stabilization of the mechanical properties of iron tailings soil. The results show that in the cement system, ISS weakens the mechanical properties of cement mortar. When ISS content is 1.67%, the 7 d compressive strength of cement mortar decreases by 59.8% compared with the reference group. This retardation arises due to carboxyl in ISS forming complexes with Ca2+, creating a barrier on cement particle surfaces, hindering the hydration reaction of the cement. In the cement-stabilized iron tailings soil system, ISS has a positive modification effect. At 0.33% ISS, compared with the reference group, the maximum dry density of the samples increased by 6.5%, the 7 d unconfined compressive strength increased by 35.3%, and the porosity decreased from 13.58% to 11.85%. This is because ISS reduces the double electric layer structure on the surface of iron tailings soil particles, reduces the electrostatic repulsion between particles, and increases the compactness of cement-stabilized iron tailings soil. In addition, the contact area between cement particles increases, the reaction energy barrier height decreases, the formation of Ca(COOH)2 reduces, and the retarding effect on hydration weakens. Consequently, ISS exerts a beneficial effect on augmenting the mechanical performance of cement-stabilized iron tailings soil.

This article discusses the utilization of industrial construction waste for resource recycling and disposal. It focuses on researching a new water-resistant, self-healing soil curing technology called road liquid, which is a fly ash-based soil curing agent. This technology is used for the curing of industrial construction waste disposal methods. For the first time, the soil curing agent is mixed into the construction waste along with cement stabilization. Different amounts of mixing are used as controls to evaluate the performance of the curing material after the construction waste is cured. The study focused on the material properties of cured construction waste, specifically examining strength, water resistance, and self-healing properties. The study showed that the curing agent road liquid enhanced the strength, water resistance, and self-healing properties of the cured construction waste at various cement dosages. The 7-day unconfined compressive strength of recycled aggregates with a 5% cement dosage, added with the curing agent road liquid, was higher than that of recycled aggregates with a 6% cement dosage without the curing agent road liquid. The experimental results show that using this type of granular solid waste as pavement base material is more practical for engineering purposes. The curing agent road liquid can enhance the curing effect of recycled aggregate, thereby reducing the need for cementitious materials and achieving cost savings for the project.

In recent decades, rapid urbanization has generated a large amount of waste soft soil and construction debris, resulting in severe environmental pollution and posing significant challenges to engineering construction. To address this issue, this study explores an innovative approach that synergistically applies recycled fine aggregate (RFA) and soil stabilizers to improve the mechanical properties of soft soil. Through laboratory experiments, the study systematically examines the effects of different mixing ratios of RFA (20%, 40%, 60%) and soil stabilizers (10%, 15%, 20%) with red clay. After standard curing, the samples underwent water immersion maintenance for varying durations (1, 5, 20, and 40 days). Unconfined compressive strength (UCS) tests were conducted to evaluate the mechanical performance of the samples, and the mechanisms were further analyzed using scanning electron microscopy (SEM) and particle size distribution (PSD) analysis. The results indicate that the optimal performance is achieved with 20% RFA and 20% stabilizer, reaching the highest UCS value after 40 days of water immersion. This improvement is primarily attributed to the formation of a dense reticulated structure, where RFA particles are effectively encapsulated by clay particles and stabilized by hydration products from the stabilizer, forming a robust structural system. Unconsolidated undrained (UU) tests reveal that peak deviatoric stress increases with confining pressure and stabilizer content but decreases when excessive RFA is added. Shear strength parameter analysis demonstrates that both the internal friction angle (phi) and cohesion (c) are closely related to the content ratios, with the best performance observed at 20% stabilizer and 20% RFA. PSD analysis further confirms that increasing stabilizer content enhances particle aggregation, while SEM observations visually illustrate a denser microstructure. These findings provide a feasible solution for waste soft soil treatment and resource utilization of construction debris, as well as critical technical support and theoretical guidance for geotechnical engineering practices in high-moisture environments.

In the context of efforts aimed at reducing carbon emissions, the utilization of recycled aggregate soil mixes for soil stabilization has garnered considerable interest. This study examines the mechanical properties of mixed soil samples, varying by dosage of a soft soil curing agent C, recycled aggregate R content, and curing duration. Mechanical evaluations were conducted using unconfined compressive strength tests (UCS), field emission scanning electron microscopy (FESEM), and laser diffraction particle size meter tests (PSD). The results indicate that the strength of the mixed soil samples first increases and then decreases with higher dosages of recycled aggregate, reaching optimal strength at a 20% dosage. Similarly, an increase in curing agent dosage enhances the strength, peaking at 20%. The maximum strength of the mixed soils is achieved at 28 days under various proportions. The introduction of the curing agent leads to the formation of a flocculent structure, as observed in FESEM, which contributes to the enhanced strength of the soil mixes. Specimens prepared with a combination of 20% R and 20% C, maintained at a constant moisture content of 20%, and cured for 28 days exhibit a balance between economic, environmental, and engineering performance.

Urban construction generates significant amounts of construction residue soil. This paper introduces a novel soil stabilizer based on industrial waste to improve its utilization. This stabilizer is primarily composed of blast furnace slag (BFS), steel slag (SS), phosphogypsum (PG), and other additives, which enhance soil strength through physical and chemical processes. This study investigated the mechanical properties of construction residue soil cured with this stabilizer, focusing on the effects of organic matter content (Oo), stabilizer dosage (Oc), and curing age (T) on unconfined compressive strength (UCS). Additionally, water stability and wet-dry cycle tests of the stabilized soil were conducted to assess long-term performance. According to the findings, the UCS increased with the higher stabilizer dosage and longer curing periods but reduced with the higher organic matter content. A stabilizer content of 15-20% is recommended for optimal stabilization efficacy and cost-efficiency in engineering applications. The samples lost their strength when immersed in water. However, adding more stabilizers to the soil can effectively enhance its water stability. Under wet-dry cycle conditions, the UCS initially increased and then decreased, remaining lower than that of samples cured under standard conditions. The findings can provide valuable data for the practical application in construction residual soil stabilization.

This Study is focused on suitability of industrial wastes in cement stabilized soil. The investigation is based on Unconfined compressive strength (UCS) tests. Experimental work is carried out to compare the UCS of cement stabilized soil specimens with different proportion of industrial wastes like Iron ore tailing, Quarry dust, Fly ash and Bagasse ash. The mix proportion is designed such that clay content is maintained at 10.5% for fine grained soil and density of 17.5 kN/m3. It is observed that the mix comprising industrial wastes and fiber have improved the mechanical properties compared to cement stabilized soil. Fiber addition has improved post peak behavior of soil specimen. The Scanning Electron Microscopy (SEM) microstructure images depict soil particle flocculation, leading to an increase in compressive strength and Energy Dispersive X-ray Spectroscopy (EDS) studies suggest the use of industrial wastes with natural soil helps in strengthening of soil cement stabilization, as well as to minimize the environmental pollution.

This paper utilizes both the ionic soil stabilizer (ISS) and sand to strengthen bentonite, as ISS effectively reduces its expansive properties and sand rapidly improves its strength to reduce cracks. Various experiments are conducted to analyze the changes in physical and mechanical properties of the bentonite strengthened by ISS-sand (ISB). The results show that not only do the sand particles enhance the strength of bentonite, but also the ISS significantly reduces its expansibility. Furthermore, the mass ratio of sand to bentonite has different effects on the unconfined compressive strength (UCS) and the freeze-tolerance of sand-reinforced bentonite (SB) and ISB. These findings suggest that a comprehensive consideration of the sand mixing rate is necessary when implementing ISS reinforcement on natural expansive soil.