Ionic Soil Stabilizer Research Articles

Effect of ionic soil stabilizer on the properties of lime and fly ash stabilized iron tailings as pavement base

The large use of iron tailings is in urgent need given its huge emissions and pollution to environment. This paper sought to utilize a large quantity of iron tailings with fly ash and lime to prepare road base materials, and use ionic soil stabilizer (ISS) to improve its pavement performance. Different dosage ISS content of was added to the lime-fly ash stabilized iron tailing materials to improve the mechanical strength, frost resistance properties and decrease the dry shrinkage. The results show that the UCS of the specimen with 0.67 % ISS represents enhancement of 195.5 % compared to the control sample at 7 d. After undergoing 15 freeze-thaw cycles, the residual UCS ratio remains at 76.6 %, whereas the control sample exhibits signs of failure. Additionally, the dry shrinkage strain at 30 d was 66.3 % lower than that of the control sample without ISS. The mechanisms underlie that the adsorbed ISS onto iron tailings can reduce the repulsion between total fine particles by lowering the general zeta potential, thus decreasing the porosity of the road base materials. Besides, the ISS can hinder the phase transformation from ettringite (AFt) to monosulfoaluminate (AFm) and its hydrophobic groups can prevent the infiltration and migration of water. The findings reveal that ISS significantly enhances the pavement performance of the stabilized iron tailings, thereby presenting a novel approach for the incorporation of iron tailings in road construction endeavors.

Experimental study on the effects of composite reinforcement of ionic soil stabilizer and sand on bentonite

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.

Experimental study on ionic soil stabilizer combined with vacuum preloading to solidify sludge

Experimental study on ionic soil stabilizer combined with vacuum preloading to solidify sludge

Mechanism of Rapid Solidification Sludge with Soil Stabilizer Based on Calcium Sulfoaluminate Cement

In this study, a composite rapid soil stabilizer (CRSS) was developed based on a calcium sulfoaluminate cement (CSA) to enhance the rapid solidification performance of sludge soil and augment its deficient engineering properties. The appropriate admixture type and dosage were determined through a double mixing test, and the stabilizer formula was optimized via response surface analysis. The solidification products and micromorphology were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the solidification mechanism was discussed. The results showed that the unconfined compressive strength (UCS) of the CRSS-solidified sludge cured for 1 day reached 9 MPa, which was approximately 5 times higher than that of sludge solidified by early strength composite portland cement (PC 42.5R). Gypsum, lithium salt, and ionic soil stabilizer addition significantly affected the strength of the CSA-solidified sludge.

Study on Strength and Microstructure of Red Clay Reinforced by F1 Ionic Soil Stabilizer

High-liquid limit red clay has poor engineering characteristics, namely poor water stability, low strength, and large expansion and contraction deformation. The clay may be reinforced with an F1 ionic soil stabilizer. The engineering characteristics of this reinforced clay were studied, specifically concerning its basic physical parameters, shear strength parameters, and micropore structure. The F1 ionic soil stabilizer significantly improved the water sensitivity, compaction characteristics, and shear strength of red clay. We determined that the optimal F1 ionic soil stabilizer mix was 0.5 L/m3, resulting in a reinforced clay with plastic limit increased by 45.74%, optimal moisture content increased by 12.12%, maximum dry density increased by 5.8%, liquid limit reduced by 8.4%, plasticity index reduced by 43.8%, infiltration coefficient reduced by 41.8%, cohesion increased 1.64-fold, and internal friction angle increased 1.30-fold. Freeze-thaw cycles reduced the shear strength parameters of the reinforced red clay, although even after 15 cycles, it still had 18.4% higher cohesion and 57.1% higher internal friction angle than undisturbed red clay. The F1 ionic soil stabilizer significantly reduced the pore size and area of red clay, the complex connected pore structure is adjusted to a more regular structure. The reinforced clay had 56.64% lower pore area ratio, 32.27% lower average Feret diameter, and 2.43% lower fractal dimension.

Experimental Study on Strength and Microstructure of Glacial Till Stabilized by Ionic Soil Stabilizer

Glacial till, widely distributed in southwest China, is a special soil directly deposited by detritus formed from melting Quaternary glaciers. In this paper, the F1 ionic soil stabilizer was adopted for stabilizing the glacial till to improve its mechanical strength. A series of micro and macro tests were carried out to study the mechanical properties and microstructure of stabilized soil with the F1 ionic soil stabilizer. The results show that the F1 ionic soil stabilizer can destroy the diffuse double layer structure on the surface of glacial till particles and reduce the thickness of the adsorbed water layer through strong cation exchange and hydrophobic interactions of active sulfonated oil, which reduce the spacing of glacial till particles, enhance the aggregation of glacial till particles, and effectively suppress the swelling deformation of the glacial till. It can be concluded that the water sensitivity and compaction characteristics of glacial till can be significantly improved by the stabilization of the F1 ionic soil stabilizer. Moreover, the mechanical strength of the glacial till can be significantly improved by the stabilization of the F1 ionic soil stabilizer. This article is helpful as a guideline for practical design and future research on applying the F1 ionic soil stabilizer to improve the bearing capacity of foundations in glacial till areas.

Preliminary study on preparation of unfired bricks using filter cake from tunnel muck

Disposal of tunnel muck is a thorny issue in tunnel construction, which has adverse social, environmental and economic impacts. At present, the gravel, sand and water in the tunnel muck can be reasonably recycled, while filter cake (FC), the clay content in the tunnel muck, is still treated by landfill. In this work, based on a comprehensive test plan with three parameters and five variations for each parameter, FC was initially used to prepare unfired bricks, and the possibility of resource utilization of FC was explored. Furthermore, unconfined compressive strength and water resistance of unfired bricks were systematically investigated. Results showed that the maximum strength of the prepared unfired brick samples could reach 25.7 MPa which achieved the requirements of MU25, and the incorporation of an appropriate amount of waste red brick powder (WRBP) and ionic soil stabilizer (ISS) could significantly improve the unconfined compressive strength and water resistance of unfired bricks. Therefore, FC had great potential to replace clay to prepare unfired bricks instead of being deposited as wastes.

Durability of solidified sludge with composite rapid soil stabilizer under wetting–drying cycles

Composite rapid soil stabilizer (CRSS) comprising calcium sulfoaluminate cement, gypsum, lithium carbonate, and ionic soil stabilizer is characterized by rapid hardening and high strength. In this study, it was used to solidify sludge rapidly, and how the number of wetting–drying (WD) cycles and the CRSS dosage influenced the durability of the solidified sludge was studied. The results show that for a given CRSS dosage but an increasing number of WD cycles, the dry mass and density of the solidified sludge decreased, the water content and pH of the soaking solution increased, the unconfined compressive strength increased slightly, then decreased slowly, finally stabilized. The ettringite in the solidified sludge was transformed from columnar to needle-like. the diffraction peak intensity decreased, and the microscopic pores increased in both size and quantity. With increasing CRSS dosage, the apparent structure was more intact, the strength attenuation was smaller. After 12 WD cycles, with a 20% content of solidified sludge, the dry mass loss was only 2%, the strength loss was only 12%, and the cumulative pore volume did not increase obviously, which was maintained at about 0.20 ml/g, showing the high resistance to WD erosion. Based on the chemical reaction and combined with the macroscopic and microscopic test results, the microscopic evolution mechanism of the durability of solidified sludge under WD cycles—especially the strength evolution mechanism—is revealed clearly. The solidified sludge with CRSS had good durability against WD cycles, thereby laying a theoretical foundation for applications of CRSS.

A novel countermeasure for preventing scour around monopile foundations using Ionic Soil Stabilizer solidified slurry

A novel scour prevention countermeasure of using the Ionic Soil Stabilizer (ISS) solidified slurry was investigated in this study. The ISS-solidified slurry is composed of Ionic Soil Stabilizer, Dispersion Resistance Agent (DRA), silt (or silty clay) and distilled water. It can be placed on the seabed immediately after monopile was installed, or in the developed scour holes. In present study, the first type was adopted as the scour protection layer around monopile. The scour morphology and the performance of scour protection layer was firstly analyzed based on flume experimental results. Furthermore, the falling head permeability tests, Zeta potential tests and scanning electron microscope (SEM) tests were carried out to investigate the scour protection mechanism of ISS-solidified slurry. Finally, the performance of the ISS-solidified slurry as scour protection layer was remarked comprehensively. The results indicate that the ISS-solidified slurry for scour protection is favorable and cost-effectiveness. Compared with the untreated seabed, the ISS-solidified slurry layer can bear with the greater critical shear stress required for the initial scour. The DRA can keep the fluidity of ISS-solidified slurry within an appropriate range and facilitate the hardening process in water simultaneously, so the DRA is indispensable for ISS-solidified slurry when it is used as scour protection layer in field.

Scour Protection of Submarine Pipelines Using Ionic Soil Stabilizer Solidified Soil

A novel scour protection approach for pipeline using the Ionic Soil Stabilizer (ISS) solidified soil was proposed in this study. The ISS-solidified slurry can be poured adjacent to the pipeline immediately after it was placed, or in the growing scour holes. In the present study, the first type was utilized as the scour protection layer around the pipeline. A series of laboratory flume tests were conducted to validate the protective capacity of ISS-solidified slurry for the pipeline in waves and combined waves and current. Then, the scanning electron microscope (SEM) tests and pore size tests were carried out, respectively, to investigate the mechanism of ISS-solidified slurry for scour protection around the pipeline. Finally, the effects of the ISS-solidified layer for liquefaction stability of non-cohesive subsoil were evaluated. The results indicated that the ISS-solidified slurry is a reliable, economic approach for scour protection around pipelines in the ocean environment. It is noteworthy that if a non-cohesive soil layer underlies the ISS-solidified slurry, it is vulnerable to suffer accumulated liquefaction due to the dense crust structure of the ISS-solidified layer, so the adverse effects for accumulated liquefaction should be considered carefully due to the set of the ISS-solidified layer.

An Experimental Study on the Stabilization of Bentonite Treated with a Composite Reinforcement Made of Sand and an Ionic Soil Stabilizer

As an ionic soil stabilizer (ISS) can effectively reduce the expansive properties of bentonite and sand can improve the strength of a soil rapidly thereby reducing the likelihood of cracks, in the present study, these two methods are combined to strengthen bentonite. Different experiments are carried out and the results confirm that the proposed strategy can effectively be used to improve the properties of this material. It is also shown that the sand-to-bentonite mass ratio has different effects on the unconfined compressive strength (UCS) of the SB (sand strengthened) and ISB (ISS-sand composite strengthened bentonite) samples. The UCS of these two samples both attenuates significantly after one freeze-thaw cycle and then display only minor changes after multiple cycles.

Influencing the Efficacy of Widespread Use of Ionic Soil Stabilization Techniques for Improving Expansive Clay Soil Properties

<i>Background</i>: Geotechnical engineers working on the ground face a common obstacle of unsuitable soil. Expansive soil is one of the soils vulnerable to high loads and unstable. Properties such as high permeability, low bearing capacity, compression, swelling and shrinkage behavior, low strength and stiffness are all characteristics of an expanding soil. Expansive soil is weaker than other soil types due to these characteristics. <i>Objective</i>: This study aimed to review the efficacy of the widespread use of ionic soil stabilization techniques for improving expansive clay soil properties by using different dosage levels that affect the properties of expansive clay soil. <i>Results</i>: expansive soil's high sulfate content, experiences swelling and heaving when stabilized with cement, lime, and fly flash. Engineers developed a new stabilizer called ionic soil stabilization to address this issue, improving strength and stiffness while reducing expansive soil permeability, compressibility, swelling, and shrinkage. <i>Conclusion</i>: Ionic soil stabilizer is preferred for improving clay soil because of its high efficiency and environmentally friendly stabilizer material, and low cost.

Solidification Effect and Mechanism of Marine Muck Treated with Ionic Soil Stabilizer and Cement

In this study, an environmentally friendly ionic soil stabilizer (ISS) was adopted with combination of Portland cement to stabilize a marine muck. The macro and micro tests results demonstrated that the ISS was an effective stabilizer to improve the strength of marine muck when it was used combined with cement after adding the alkalizer NaOH. Except for the reduction in interlayer distance of clay minerals by ISS, Ca2+ and SO42− dissolved from ISS promoted the production of ettringite (AFt), pozzolanic and carbonation reactions of Portland cement in the presence of NaOH. Meanwhile, the hydration products of curing reaction notably agglomerated soil particles, which caused an obvious decrease of pores and a high increase of strength for solidified soils. Furthermore, this combination of stabilizers can not only save the dosage of cement, but also accelerate the solidification speed, decrease the cement setting time within 7 days to meet the curing requirements, and enhance the strength of solidified soils.

Solidification effect and mechanism of ionic soil stabilizer applied on high-water-content clay

Solidification effect and mechanism of ionic soil stabilizer applied on high-water-content clay

Analisis Ionic Soil Stabilizer (Iss 2500) Terhadap Nilai Durabilitas Tanah Lempung Plastisitas Rendah Pada Perkerasan Jalan

Various methods of soil stabilizations in Indonesia are more increasingly used for soil quality improvement, one of the methods is using chemically additive materials with ISS 2500 (Ionic Soil Stabilizer). This chemical solution is able to cover soil particles through electro-chemical reactions, so that the water content is separated and cohesion among soil particles is strengthened. However, unstable weather and temperature changes (durability) in forms of rainfall and heat influence and cause soil defects especially in road construction. In this reseach, the tested soil was clay with low plasticity from Karang Anyar region in Lampung Selatan regency, and mixed with 0.9 ml of ISS 2500 solution content the ISS optimum content. To enable reactions between soil and ISS 2500, the mixed soil was treated in 18 days with durability treatment and cycles addition; 0,2,4, and 6 cycles. The laboratory results indicated that CBR test in cycle 0, 2, 4, and 6 obtained 8%, 7.6%, 5.7%, and 5.1% respectively. The CBR value of the mix decreased regularly along with given amounts of additional cycles. However, the overall CBR value of the stabilization of low plasticity clay with an ISS of 2500 (Ionic Soil Stabilizer) can meet the requirements of Bina Marga as subgrade, because the CBR value obtained is greater than 5% even though it is given cycle treatment. The ISS 2500 material can be used as an alternative stabilization material for the improvement of the subgrade.

Study on strength characteristics and mechanism of loess stabilized by F1 ionic soil stabilizer

Study on strength characteristics and mechanism of loess stabilized by F1 ionic soil stabilizer

Pore and compression characteristics of clay solidified by ionic soil stabilizer

It is of great significance to study the soil pore structure for soil reinforcement and ground treatment because it can be used to evaluate the solidification effect and explain the curing mechanism. The pore and compression characteristics of clay from Wuhan in China before and after solidification by ionic soil stabilizer (ISS) in different soil initial states were studied by the use of standard consolidation test, environmental scanning electron microscope analysis, specific surface area (SSA) test, and analysis by PCAS software. Results show that the influence sequence of soil initial states on the change of pore characteristics and ISS-solidification effectiveness was as follows: reducing initial water content + remolding soil > reducing initial water content > remolding soil > natural soil with high initial water content. Besides, loading can also increase the solidification effect. Compared to random and chaotic pore directions of natural clay, remolded solidified clay had a more certain direction after curing and compression. In addition, the total pore number and SSA decreased from 1190 to 756 by 36.47% and 109.690 m2/g to 87.837 m2/g by 19.92% respectively. Results indicate that ISS-clay solidification effect in practical engineering is closely related to the soil initial pre-curing state and can lead to the change of pore direction, decrease of pore number, reduction of pore size and porosity, and formation of larger aggregates.

Evolution of Pore Characteristics for Bentonite Modified by an Ionic Soil Stabilizer during Hydration Processes

An ionic soil stabilizer (ISS) is used to reinforce clay soils because the ISS can regulate the hydration processes and microstructures of clays. To evaluate the regulation of ISS, natural bentonite was modified by ISS at different concentrations in this research. Water vapour adsorption and X-ray diffraction (XRD) were carried out to interpret the hydration mechanism of bentonite. Meanwhile, an associated analysis between hydration pore structures and hydration mechanisms was implemented through variation of pore characteristic tests at different relative humidities (RHs) to distinguish multiscale pore adsorption of water during the corresponding hydration process. In addition, the pore characteristics were studied via XRD, nitrogen adsorption, and mercury injection tests. Finally, the origins that adsorbed water and pore structures changed by adding ISS were discussed. The results showed that for calcium bentonite, the cations hydrated first in the range of [Formula: see text], accompanied by the expansion of micropores. Then, adsorption occurred on the basal surface of the crystal layer in the range of [Formula: see text], with water mainly adsorbed into the mesopores. With further hydration when [Formula: see text], diffused double layer (DDL) water ceaselessly entered the macropores. Both adsorbed water and multiscale pore size decreased when ISS was added to bentonite. The origins of the reduction were the regulation of ISS to exchangeable cations and the basal surface of the crystal layer.

Optimization of Ionic Soil Stabilizer Dilution and Understanding the Mechanism in Red Clay Treatment

Due to the insufficient understanding of the mechanism for soil strengthening by using Ionic Soil Stabilizer (ISS), the application of ISS in soil treatment is limited. In this paper, red clay samples were treated by using ISS and the effects were examined by the Atterberg test and uniaxial pressure test. In order to understand the mechanism, ISS dilution‐based seepage test and ξ‐potential test have been carried out. The results show that the ISS‐Water mixture of 1 : 200 was the most effective ratio to reduce the plasticity index. The measurements indicate the thickness of the pair‐electricity layer of adjacent clay layers and the repulsion force among soil particles is reduced, which in turn enhances the attraction force of the clay layers. This process strengthens the connection among the soil particles and thus increases the strength of the soil as detected by the experimental tests.

Effect of wetting-drying cycles on surface cracking and swell-shrink behavior of expansive soil modified with ionic soil stabilizer

This paper presents the results of an experimental investigation of the effect of wetting-drying cycles on the surface cracking and swell-shrink behavior of modified expansive soils. An image processing technique was employed to understand this effect by quantifying the surface crack area density, crack number, crack length, mean crack width, and absolute shrinkage. Parameters such as height, the relative rate of expansion, and linear shrinkage were used to characterize the effect of wetting-drying cycles on the swell-shrink behavior of the specimens subjected to various overburden pressures. The results showed that the increase in the number of wetting/drying cycles accelerated the crack growth and led to the increased crack number, total crack length, and surface crack area density. Moreover, as the number of wetting/drying cycles increased, the absolute shrinkage to be on the rise, and the mean crack width exhibited fluctuation characteristics. Furthermore, the moisture content was inversely related to the crack extent. For the specimens subjected to various overburden pressures, the height and the moisture content showed a good linear relationship. With the increase in wetting/drying cycles, the relative rate of expansion of the specimen decreased. Additionally, a larger overburden pressure resulted in a lower relative rate of expansion; however, as the number of wetting/drying cycles increased, the relative rate of linear shrinkage increased and then decreased.