Properties Of Expansive Soil Research Articles

Study on the effect of water content on physical properties of bentonite.

Moisture content profoundly influences the engineering properties of expansive soil, a critical consideration in various geotechnical applications. This study delves into the intricate relationship between water content and the physical properties of bentonite, a key constituent of expansive soil. Through a comprehensive analysis encompassing fundamental physical properties, rheological characteristics, permeability behavior, and microscopic features, we elucidate the complex interplay between water content and bentonite behavior. Our investigation reveals distinct responses to varying moisture levels: at low water content (w = 50%), unsaturated samples undergo incremental density increases attributed to moisture accumulation among particles. Concomitantly, heightened pressure fosters enhanced cohesion between particles, bolstering mechanical properties and augmenting reverse osmosis capacity. Conversely, at higher water content levels (w > w saturated), the escalation of free water within soil particles triggers pronounced particle softening, overshadowing expansion effects. Consequently, cohesion diminishes, and particles exhibit micro-scale flocculation. These findings offer valuable insights into bentonite behavior under differing moisture regimes, thereby providing a robust theoretical foundation for projects requiring bentonite seepage control.

Experimental Study on the Stabilization of Expansive Soil with Blended Fine Cinder Gravel and Waste Marble Dust: A Case Study of Jimma Town

This study investigates the potential of Waste Marble Dust (WMD) and fine Cinder Gravel (CG) to enhance the engineering properties of expansive soils, which are prone to volume changes due to moisture fluctuations. The research aimed to stabilize expansive soils, classified as A-7-6(37) in the AASHTO system and CH in the USCS system, for use as sub-grade materials in road construction. Mechanical stabilization technique was used in this study. Soil material is dried in air and mixed with 8%, 12%, 16%, and 24% of CG and MD. The key findings include; Plasticity Index reduced from 34.09% to 10.28%, Free Swell Index decreased from 81.8% to 36.4%, Optimum Moisture Content decreased from 24.02% to 14.00%, Maximum Dry Density increased from 14.22 kN/m³ to 16.19 kN/m³, California Bearing Ratio (CBR) increased from 1.00% to 22.69% and Unconfined Compressive Strength (UCS) increased from 112.9 kPa to 311.7 kPa. Optimal stabilization was achieved at a 16% replacement of both WMD and CG, improving the soil's strength significantly. This study concludes that WMD and CG are effective stabilizers for expansive soils, meeting the requirements for sub-grade material in road construction and offering improved durability and performance. Keywords: Expansive soil, Stabilization, Swelling, Shrinkage, Waste marble dust, Cinder gravel, Sub-grade soil, CBR value.

Enhancing the Geotechnical Properties of Expansive Soils through Coconut Shell Ash Treatment: An Experimental Investigation

Expansive Soils (ES) present a significant challenge to civil engineering projects worldwide due to their propensity to undergo volumetric changes in response to fluctuations in the moisture content. This study examined the potential of Coconut Shell Ash (CSA) as a soil stabilizer to mitigate the adverse effects of ES. The objective was to conduct a systematic evaluation of the impact of CSA on a range of soil properties, including the plasticity index, compressive strength, shear strength, swelling potential, and compaction characteristics, across a diverse array of soil types. This study adopted a comprehensive methodology, which involved the laboratory testing of soil samples with varying proportions of CSA. The tests included the determination of the Atterberg limits, the evaluation of the compaction properties, unconfined compression tests, and swelling tests. The findings revealed significant variations in the soil properties in response to the CSA content. The plasticity index responses exhibited a range of subtle changes, with a downward trend at lower CSA concentrations and more complex behaviors at higher concentrations. The compaction characteristics exhibited alterations in the optimum moisture content and maximum dry unit weight, indicating changes in soil density and stability. Similarly, the compressive and shear strength properties exhibited fluctuations with varying CSA content, underscoring the necessity for a comprehensive assessment of soil stability under CSA-treated conditions. Additionally, swelling tests demonstrated the potential of CSA to mitigate soil expansiveness, with lower swelling percentages observed in treated soils. This study highlights the importance of considering the soil type, CSA content, and engineering requirements to optimize the effectiveness of CSA in soil stabilization applications.

The Effect of Adding Mixture of Gypsum-Lime with Geopolymer on the Properties of Swelling Soil

Abstract This study was to investigate the influence of adding optimum percentages of gypsum (G) - lime (L) mixtures (i.e. 6% lime and 4% gypsum) with three percentages of fly ash geopolymer (FAG) (i.e. 6%, 9%, and 12%) on some engineering properties of expansive soil. The tests results indicated that adding the percentages for the gypsum-lime mixture (6% lime + 4% gypsum) affected the soil’s properties by decreasing the plasticity index, swelling potential, and swelling pressure by 48.2%, 85%, and 87.9%, respectively. Adding (6% L + 4% G + 12% FAG) decreased the plasticity index, swelling potential, and swelling pressure of prepared expansive soil by about 66.1%, 96.4%, and 96.9%, respectively. The California bearing ratio increased up to 33.3% and 95.1% with the addition of (6% L + 4% G) and (6% L + 4% G + 12% FAG), respectively. Also, adding the same percentages of gypsum-lime mixture and gypsum-lime mixture with geopolymer caused increasing in Unconfined compressive strength value by 109.5% and 322.6%, respectively. The results show the significant effect of gypsum-lime mixture with geopolymer on compaction parameters of the prepared soil, so there was a decrease from 22% to 18% for the optimum moisture content and an increase from 1.473 g/cm3 to 1.516 g/cm3 for the maximum dry density.

Correlation Study of Shrinkage Expansion Potential of Clay Soil In PLTMH Cileunca, Pangalengan, Bandung, Indonesia

Mini Hydro Power Plants (MHPs) utilize the potential of water to generate electrical energy. However, construction on clay soils that have the potential to expand and contract can affect the stability of the structure. This study aims to evaluate the potential for soil development in the Cileunca MHP. The methods used to determine soil development potential include Chen (1988), Skempton (1953), and Seeds (1962) methods. Mineral identification was conducted through X-Ray Diffraction (XRD) testing of soil samples taken by the handboring method. The results of the analysis showed that the Skempton method showed 67% of the samples had activity values > 0.75 (“high” category). The Chen method indicated 60% of the samples had a plasticity index (PI) > 35% (“very high” category). The Seeds method indicated 73% of the samples had a development potential > 25% (very high category). XRD testing indicated the dominant mineral was dehydrated Halloysite (Al2Si5(OH)4). The soil at the Cileunca MHP site has a high development potential that can damage building foundations. Foundation stability is strongly influenced by expansive soil properties, so soil stabilization treatment is needed to prevent structural damage. This study concludes that the soil at the Cileunca MHP site has a high development potential, which can cause structural problems. Therefore, soil stabilization treatment is highly recommended to ensure the stability of the building foundation

Enhancing Mechanical Properties of Expansive Soil Through BOF Slag Stabilization: A Sustainable Alternative to Conventional Methods

This study investigates the stabilization of expansive soil using basic oxygen furnace (BOF) slag, an eco-friendly steel by-product, as an alternative to conventional stabilizers like ordinary Portland cement. By evaluating varying concentrations of BOF slag and lime as an activator, the research aims to improve the soil’s mechanical properties, addressing issues like low bearing capacity and high shrink–swell potential. Bentonite clay was treated with different BOF slag ratios (10%, 20%, and 30%) and activated with lime (1%, 3%, and 5%). After mixing and compaction, samples were cured and tested for unconfined compressive strength (UCS), shear wave velocity (BE), and free swell. Microscopic analyses (SEM) provided insight into structural changes post-stabilization, revealing improved properties with increased BOF and lime concentrations. Notably, stabilization with 30% BOF slag and 5% lime achieves a compressive strength of 810 kPa, meeting the minimum subgrade soil stabilization requirement (700 kPa) set by the Federal Highway Administration. This research underscores the potential of BOF slag as a sustainable and practical material for bentonite clay stabilization, offering a promising solution for enhancing soil properties while contributing to environmental sustainability through industrial by-product repurposing.

A Comparative Study of Ground Granulated Blast Furnace Slag and Bagasse Ash Incorporation on Enhancing Mechanical Properties of Expansive Soil

Expansive soils swell when wet and shrink when dry, causing differential settlements that can lead to structural failures in roads and buildings. In cases where these soils cannot be avoided, improving their stability is essential. This study investigates the use of two binders, ground granulated blast-furnace slag (GGBS) and bagasse ash (BA), byproducts of steel and sugarcane processing, respectively, to reduce soil swelling and enhance stability by assessing the mechanical behavior of reinforced expansive soil. To evaluate the behavior of reinforced expansive soils, tests such as Atterberg limits, compaction, swelling potential, and direct shear were conducted. Results indicated that as reinforcement levels increased to an optimal threshold (3% GGBS and 12% BA), the optimum moisture content rose, while maximum dry unit weight generally decreased. A 15% increase in moisture content and a 3.16% decrease in maximum dry unit weight were observed with reinforcement. Cohesion decreased by 27% in soaked conditions and 31% in unsoaked, while the angle of internal friction rose by 106% and 111%, respectively, at the maximum reinforcement threshold. These additives also improved shear strength, reduced swelling potential, and lowered plasticity index, shifting the soil behavior from clay-like to silty. The results show that bagasse ash and GGBS effectively enhance soil properties and provide a sustainable solution for soil stabilization in construction.

Influence of Agro-Industrial Waste on Unconfined Compression Strength Parameters of Expansive Soil: An Experimental Investigation

Expansive soils pose a significant challenge in construction due to their potential to cause structural damage through its swelling and shrinking characteristics. Simultaneously, the disposal of numerous industrial and agricultural wastes poses challenges that contribute to environmental ecosystem damage. This experimental study explores the effect of agro-industrial waste on the mechanical properties of expansive soil. Specifically, the impact of incorporating agro-industrial waste materials, such as bagasse ash, plastic strips, and coir fiber, is investigated through assessments of unconfined compression strength. The unconfined compressive strength (UCS) test was conducted to examine various parameters of different combinations involving expansive soil, bagasse ash, coir fiber, and plastic strips. The results demonstrated notable improvements in Unconfined Compression Strength (UCS), particularly when incorporating a specific combination of 10% Bagasse Ash, 0.5% Plastic Strips, and 0.75% Coir Fiber) which resulted in a remarkable 49% increase in UCS. The findings show that including plastic strips enhances UCS by 2%, Coir Fiber improves it by 5%, and a combination of Bagasse Ash, plastic strips, and Coir Fiber leads to a 7% increase in UCS. The study on incorporating agro-industrial waste materials, such as bagasse ash, plastic strips, and coir fiber, reveals substantial improvements in the mechanical properties of expansive soil. This study contributes to the sustainable utilization of agro-industrial waste for soil improvement, offering a promising avenue for eco-friendly geotechnical solutions. Future work could explore the long-term performance and scalability of these materials in various soil conditions.

Experimental investigation of freeze–thaw effects on the micropore properties of expansive soil using NMR–SEM techniques

Experimental investigation of freeze–thaw effects on the micropore properties of expansive soil using NMR–SEM techniques

Expansive clay subgrade soil improvement using municipal solid waste fly ash: Experimental and numerical approach

The expansive soil under investigation has caused damage to lightweight structures due to its swelling and shrinkage characteristics in response to changing moisture content. The study aims to assess the impact of municipal solid waste (MSW) fly ash on the engineering properties of subgrade expansive soils and its influence on pavement structure deformation. The influence of municipal solid waste fly ash on expansive soils was evaluated using laboratory tests and finite element methods. The Abaqus software was used to investigate the effects of MSW fly ash on pavement structure deformation. The input parameters employed for this analysis were elastic modulus, Poisson ratio, load, contact area dimension, and pavement layer thickness. To mitigate this issue, MSW fly ash was used as a stabilizing agent at varying percentages (5 %, 10 %, 15 %, 20 %, 25 %, and 30 % of the dry mass of the soil sample).According to the AASHTO soil classification, the soil is classified as A-7, has a high free swell, a low soaked CBR value, and a high soaked CBR swell, and does not meet the ERA manual standard for subgrade materials. The laboratory tests shown several improvements in the engineering properties of expansive soil when MSW fly ash were mixed. These improvements included a reduction of soaked CBR swelling, free swell index, plasticity index, specific gravity, optimum moisture content. Additionally, the maximum dry density and soaked CBR values increased. Numerical analysis using Abaqus software focused on vertical deformation of the pavement structure. The results showed that as the percentage of MSW fly ash in form 0 % to 25 % of soil dry weight, the vertical deformation of the pavement structure decreased from 0.84 mm to 0.67 mm. This demonstrates that the addition of MSW fly ash reduced the deformation of expansive sub-grade soil and improved the engineering qualities of pavement structure. In conclusion, the study revealed that the use of MSW fly ash as stabilizing agent effectively reduced the deformation of expansive subgrade soil and improved the engineering qualities of pavement structure.

Comparative study on mechanical performance of silty soil and expansive soil below canal structures in cold regions

Silty soil was widely used as filling soil materials for the replacement of expansive soil in cold regions. This paper presents a straightforward approach for the effects of wetting-drying-freezing-thawing cycles on mechanical behaviors of silty soil and expansive soil by laboratory tests. The results showed that the silty soil and expansive soil after 7th wetting-drying-freezing-thawing cycles presented the decreases of elastic modulus, failure strength, cohesion and angel of internal friction by 8.9 %∼12.0 %, 7.7 %∼9.0 %, 7.9 %, 4.5 % and 17.6 %∼37.0 %, 20.5 %∼29.4 %, 43.2 %, 13.0 %, respectively, indicating that wetting-drying-freezing-thawing cycles had little impact on mechanical property of silty soil and a great influence on that of expansive soil. Among them, the mechanical property attenuation ratio in the first three wetting-drying-freezing-thawing cycles accounted for over 90 % of the total. In the meantime, the micro-structure damage, surface crack characteristics and grain size distribution variations of expansive soil were all more significantly than these of silty soil exposed to wetting-drying-freezing-thawing cycles, which brought insight into the causes of the differences in mechanical properties for silty soil and expansive soil. It is found that the silty soil properties were more stable than expansive soil properties, and the silty soil is very effective for replacing the expansive soil below canal structures in cold regions.

Failure Mechanisms and Protection Measures for Expansive Soil Slopes: A Review

Due to the significant hydrophilicity and cracking properties of expansive soils, expansive soil slopes are prone to destabilization and landslides after rainfall, seriously threatening the safety of buildings, highways, and railroads. Substantial economic losses often accompany the occurrence of expansive soil slope disasters; thus, it is of great significance to understand the slope failure mechanisms experienced by expansive soil slopes and to prevent expansive soil slope disasters. In this paper, the current research status of the landslide failure mechanism of expansive soil slopes is systematically reviewed based on three research methods: field test, model test, and numerical simulation. The failure mechanisms of expansive soil slopes and the main influencing factors are summarized. Based on the failure mechanisms, three protection principles (waterproofing and water blocking, swelling–shrinkage deformation limitation, and crack inhibition and strength enhancement) that can be followed for disaster prevention of expansive soil slopes are proposed. The research status and advantages and disadvantages of these protection methods are reviewed, and future researchable directions of the stability of expansive soil slopes and slope protection methods are explored. Based on the previous work, a new flexible ecological slope protection system with a double waterproof layer is proposed for expansive soil slopes to realize ecological, efficient, and long-term protection. This paper thus aims to provide technical reference for the prevention and control of slope engineering disasters in expansive soil areas.

The Impact of Cement on the Mechanical Properties of Expansive Soil

The Impact of Cement on the Mechanical Properties of Expansive Soil

Modifying Expansive Soil Characteristics with Xanthan Biopolymer Integration

Abstract: Expansive soils pose significant challenges in various engineering projects due to their tendency to swell and shrink with changes in moisture content. Traditional stabilization methods often come with environmental and economic drawbacks. This research paper explores the potential of xanthan biopolymer, a polysaccharide of microbial origin (Xanthomonas Campestris), as a sustainable and effective alternative for altering the engineering properties of expansive soils. Through laboratory experiments and analysis, the paper investigates the influence of xanthan biopolymer on key soil properties such as swelling behaviour, shear strength, and permeability. The findings provide insights into the feasibility and efficacy of using xanthan biopolymer for soil stabilization, offering a promising avenue for sustainable geotechnical engineering practices.

A Comprehensive Review of the Evaluation and Application of Engineering Properties of Expansive Soil Based on Piezocone Penetration Test (CPTU)

Expansive soil presents several challenges in civil and geotechnical engineering because of its distinctive physical and mechanical properties, including considerable volumetric fluctuations, non-linear stress–strain behaviour, and high permeability. Owing to soil disturbances and sample size limitations during sampling, important parameters such as the expansive soil expansion force, compressive strength, and shear strength obtained through indoor experiments often cannot accurately reflect the values in situ. In this regard, in situ piezocone penetration testing has the advantages of small disturbances and high efficiency and has been widely used in subways, bridges, highways, and other engineering projects. This paper comprehensively summarizes the research progress of in situ testing technology in the evaluation and application of engineering properties of expansive soils in China and internationally. First, a detailed analysis of the basic theories and physical mechanisms of various in situ testing methods is provided, focusing on their applicability and accuracy in expansive soils. Second, examples of the application of in situ testing technology in expansive soil engineering are summarized. Finally, predictive models and methods based on in situ testing data, especially those that introduce cutting-edge models such as machine learning and advanced data analysis techniques, are discussed.

Effects of oil palm mesocarp fibers on the physical and mechanical properties of expansive soils

Palm fiber is one of the favorable materials used in stabilization of soft soil in geotechnical engineering projects, nowadays due to its sustainability, less damage of environment, biodegradability, availability and cost-effectiveness in a context of widespread appeal to the world for return to nature by protecting the earth. On the other hand, expansive soils are renowned for their swelling-shrinkage property and these volumetric changes resultantly cause huge damage to civil infrastructures. Likewise, subgrades consisting of expansive soils instigate serviceability failures in pavements across various regions worldwide. This paper presents results of the laboratory evaluation of expansive soils stabilized with oil palm mesocarp fiber (OPMF), with a view to determine its suitability as flexible pavement construction material. The mixtures were subjected to British Standard heavy (modified Proctor) compaction energy to determine their strength characteristics. The samples were subjected to different tests to ascertain their index properties. Varying proportions of OPMF from 1% to 4% were incorporated into the soil samples and the effects were observed based on compaction and California Bearing Ratio (CBR) results. The control samples without inclusion of OPMF achieved the highest Maximum Dry Densities (MDD), the MDDs reduced linearly as the OPMF content increased. Consequently, the CBR values decreased with increase in OPMF. The reduction in MDD ranged from 20.28g/cm3, 18.5 g/cm3, 15.65 g/cm3, 12.53 g/cm3 as the OPMF increased from 1%, 2% to 3%, 4%. and the optimum moisture content remained almost unaffected due to high-absorbent nature of the fibers. With the inclusion of the OPMF, the CBR value under soaked conditions dropped from 5% to 1.8% rendering them very unsuitable for pavement subgrade. It was concluded that the presence of fiber depreciated the engineering properties of the earth materials. Direct application of OPMF in any part of road pavement has been dissuaded.

Influence of Feldspar Addition on the Geotechnical Properties of Expansive Soil in Rahhaliya, Iraq

Influence of Feldspar Addition on the Geotechnical Properties of Expansive Soil in Rahhaliya, Iraq

Effects of Lime on Bagasse Ash-Stabilised Expansive Soils

Management of agricultural wastes and improvement of construction soils have become increasingly necessary for sustainable development. This study therefore stabilised selected expansive soils using bagasse ash (BA) and lime, with a view to determining the effect of lime on BA-stabilised soils. Two soil samples (identified as Sample A and Sample B) were collected from two identified locations characterised with expansive soils in Ile-Ife, Osun State, Southwestern Nigeria. Using standard procedures, the following preliminary and geotechnical tests were conducted on the soil samples in their natural state: moisture content determination, particle size analysis, specific gravity, Atterberg limits, compaction and unconfined compressive strength (UCS). BA was then introduced to the soils in 5 %, 10 % and 15 % proportions by weight of dry soil. Thereafter, Atterberg limits and UCS tests were conducted on the BA-stabilised soils. Also 2.5 % lime was introduced to each proportion of BA earlier used. Atterberg limits and UCS tests were then conducted on the BA-lime stabilised soils. Results showed that the two soils in their natural state have high plasticity and they both belong to the A-2-7 group. For both BA and BA-lime stabilised soil samples, plasticity reduced with increase in the stabilisers, which implies an improvement in the soil properties. Also, UCS of both BA and BA-lime stabilised soil samples increased with optimum values at 10 % BA content. Expectedly, addition of lime increased the values of UCS for each combination of stabilisers. It was concluded that BA could be used to improve the properties of expansive soils and that the addition of certain proportions of lime does not have a negative impact on the stabilisation properties of BA, but rather improves it.

Model Studies on Settlement of an Expansive Soil Slope Stabilized with GGBS

Expansive soils present significant challenges in civil engineering due to their tendency to undergo volumetric changes with variations in moisture content, often resulting in slope instability and settlement issues. This study investigates the effectiveness of stabilizing expansive soil slopes using Ground Granulated Blast Furnace Slag (GGBS) as an additive. The research employs laboratory-scale model studies to simulate the behaviour of expansive soil slopes subjected to varying levels of GGBS stabilization. The settlement characteristics of the stabilized slopes are analysed under different loading conditions and moisture contents. Experimental results indicate that the incorporation of GGBS enhances the properties of expansive soils, reducing settlement and improving slope stability. The findings contribute to the understanding of sustainable solutions for mitigating settlement issues in expansive soil slopes, offering insights for practical applications in geotechnical engineering.

Mechanical and Microstructural Changes in Expansive Soils Treated with Lime and Lignin Fiber from Paper Industry

Expansive soil exhibits significant swellings and shrinkages, which may result in severe damage or the collapse of structures built upon it. Calcium-based admixtures, such as lime, are commonly used to improve this problematic soil. However, traditional chemical additions can increase significant environmental stress. This paper proposes a sustainable solution, namely, the use of lignin fiber (LF) from the paper industry to partially replace lime as an amendment for expansive soils. Both the macroscopic and microscopic characteristics of the lignin fiber-treated expansive soil are extensively studied. The results show that the mechanical properties of expansive soil are improved by using lignin fiber alone. Under the condition of an optimal dosage of 8%, the compressive strength of lignin fiber-modified soil can reach 193 kPa, the shear strength is increased by 40% compared with the untreated soil, and the water conductivity is also improved with the increase in dosage. In addition, compared with 2% lime-modified soil, the compressive strength of 8% lignin fiber- and 2% lime composite-treated expansive soil increased by 50%, the cohesion increased by 12%, and the water conductivity decreased significantly. The microstructure analysis shows that at an 8% lignin fiber content, lignin fibers interweave into a network in the soil, which effectively enhances the strength and stability of the improved soil. Simultaneously, the fibers can form bridges across the adjacent micropores, leading to the merging of pores and transforming fine, dispersed micropores into larger, connected macropores. Lime promotes the flocculation of soil particles, forming larger aggregates and thus resulting in larger pores. The addition of fibers exerts an inhibitory effect on the flocculation reaction in the composite-improved soil. In conclusion, lignin fibers are an effective addition used to partially replace calcium admixture for the treatment of expansive soil, which provides a sustainable and environmentally friendly treatment scheme for reducing industrial waste.