Plastic Clay Soil Research Articles

Evaluation of the Contribution of Bayburt Tuffite (Bayburt Stone) Dust to the After Freeze-Thaw Strength Values of High Plasticity Clay Soils

The strength properties of soils that are considered problematic, such as high plasticity clay, need to be improved for the increasing housing needs in parallel with the increasing population growth and the evolving needs of society due to continuous technological developments. In the last twenties, when global climate changes began to occur, improving the geotechnical properties of such soils, which form the basis of engineering structures, has become an important issue. For this reason, many studies have begun to improve and strengthen such soils using natural, synthetic, or various chemicals. For this reason, natural rocks are one step ahead of other healing materials in terms of being economical, sustainable, and environmentally friendly. In our study, Bayburt tuffite was added to the clayey soil by pulverizing it at the rates of 5%, 10%, and 15%, and the strength change after freezing and thawing was examined. Clay soil (CS) + Bayburt tuffite powder (BTP) mixture samples obtained in three different ratios were wrapped with stretch wrap in the laboratory environment (+20oC) and cured for 7, 14, and 28 days, ensuring the opt. moisture content was maintained. At the end of the curing period, the samples were subjected to +20oC, -20oC, 12 hours, and 10 cycles in the freeze-thaw cabinet, and then, Strength values were acquired with a uniaxial testing device. The highest strength value after freezing-thawing; was observed that it was 29.55% in the MIX1 (CS + 5% BTP) mixture cured for 28 days. As a result, it was concluded that this mixing ratio can be used in cold climates and shallow foundation depths with high plasticity clay soil properties.

Cement kiln dust and polypropylene fiber in expansive clay improvement

For civil engineers, expansive soils pose a great deal of difficulty because of their sensitivity to volume changes with different moisture levels. These difficulties are compounded by the widespread occurrence of swelling clay, which can seriously harm infrastructure, especially in arid or semi-arid areas. The geotechnical qualities of these soils have been improved through the use of various additives and techniques, resolving this problem and making the soils suitable for building. Numerous stabilization techniques, nevertheless, may have negative environmental effects. Therefore, it is imperative to investigate the use of local waste or by-products to stabilize soil in order to preserve the environment and lower stabilization costs, especially in road construction projects.To address these issues, an experiment was conducted to determine how locally obtained cement kiln dust (CKD), both alone and combined with polypropylene fibers, affected the properties of plastic clay soil, also referred to as expansive clay from Cheffia.The main objective of this study is to assess how well different CKD percentages (from 5% to 25%) stabilize soil while improving its mechanical and physical properties. The study also aims to explain how the addition of polypropylene fiber affects the unconfined compressive strength and compaction behavior of the soil in the optimal CKD-soil mixture. The results of the analysis show that the addition of cement kiln dust (CKD) significantly improved the studied soil's workability, compaction, and strength. Additionally, adding polypropylene fibers strengthens the clay's resistance to compression, which presents encouraging opportunities for reducing the difficulties brought on by expansive soils in civil engineering applications.

Effects of Bio-enzyme on the strength properties of soil

Engineers regularly attribute the complexity of constructing parts on or by soils, those do not have sufficient strength to sustain the loads required leading them either all over construction or in the study life of the structure. The more areas of India shows of CH (Inorganic Clay of High Plasticity) clay soil characterized by more small portion, lower shear strength and lesser bearing capability. The unfortunate engineering performances of these soils has enforced Engineers to instrument charge competent and eco-friendly processes for increasing the engineering properties of these soils. As the conservative soil stabilizers like gravel, sand, etc. Are declining and suitable expensive day by day at an extremely quick rate, it becomes necessary to emerge for possible ecological stabilizers as their substitute. In current scenario the various Bio-enzymes have emerged as lesser cost stabilizers for soil stabilization. Bio-enzyme is a common, harmless, non-flammable, noncorrosive liquid enzyme formulation fermented from vegetable forms that creates the engineering behavior of soil, generates more soil compaction densities and more stability. One such Bio-enzyme, Terrazyme, has been applied in the current occupation to study its consequence on Atterberg Limits, Unconfined Compressive strength, and shear strength parameters of a CH soil. It has been confirmed that Terrazyme purifications of CH soil outcome in main development in Unconfined Compressive strength and Shear Strength parameters separately from Index characteristics. The entire characteristics are reliant on remedial time also. There is a specific best concentration for each characteristic in concern and it ranges from 0.2 ​ml/kg and 0.4 ​ml/kg of soil. Although, the more plastic clay soil is get to be addition responsive to Terrazyme purifications.

Investigation of constitutive properties of high plasticity clay soils mixed with crushed rubber tire waste

Addressing the enormous waste resulting from discarded worn rubber tires is an environmental challenge. Recycling and using crushed rubber tire waste (CRTW) in construction materials can help in addressing this challenge. This study investigates the effect of addition of CRTW on the engineering properties of high plasticity clay soils (HPCS). There is a paucity of research in the application of CRTW in HPCS. This research tries to fill this research gap. Specifically, this study seeks to investigate the effect of mixing CRTW on the constitutive properties of HPCS. After identifying a locally available HPCS, mixtures of the clay and several percentages (0%, 6%, 12%, 18%, and 24%) by weight of CRTW were prepared. A range of CRTW shapes and sizes were investigated. Three different particle shapes of CRTW (granular rubber, rubber chips, and rubber fiber), and two particle sizes (fine and coarse) were studied. The parameters studied included unconfined compressive strength (UCS), strain at failure, post-peak strength loss (PPSL), modulus of elasticity, failure modes/mechanisms, repeatability of tests results, and examination of CRTW particles and mixtures via binocular and SEM microscope. Our findings unveiled that the highest level of repeatability was observed in granular CRTW, with a maximum variability of only 5%. Moreover, the mixtures containing granular CRTW exhibited, on average, 10% and 15% higher strength and modulus of elasticity, respectively, in comparison to mixtures incorporating other shapes of CRTW. In general, the HPCS-CRTW mixtures displayed higher shear strains, averaging 25% greater than pure HPCS. Furthermore, the addition of CRTW to HPCS resulted in a reduction of its PPSL and a transition in behavior from brittle to slightly ductile. Examination of failed specimens revealed the existence of two primary failure modes: shear plane failure and shear plane failure accompanied by multiple vertical cracks within the mixtures. These results suggest that the utilization of granular CRTW in HPCS can improve certain properties of HPCS. However, it is advisable to limit the rubber content in this mixture to 6% to mitigate significant adverse effects on its strength.

Contribution of agricultural ashes and HDPE as a waste material for a sustainable environment applied to the stabilization of a low plasticity clay soil

Contribution of agricultural ashes and HDPE as a waste material for a sustainable environment applied to the stabilization of a low plasticity clay soil

Effect of Zeolite Mixture Percentage on the Free Compressive Strength Test Value of Clay Soil in Pulo Padang Village in Mandailing Natal Regency

High plasticity clay soils which are often encountered in field construction work have low bearing strength and large volume changes (shrinkage expansion). Soil will expand when the pores are filled with water and will shrink in dry conditions. This makes the soil unstable, and it is unable to support a building construction. Therefore, soil improvement efforts are needed to increase this soft clay soil. Soil stabilization is a soil improvement effort to strengthen soil that has low bearing capacity. In this research, the soil stabilization method is carried out using mixed materials to reduce or eliminate the unfavorable properties of the soil to be used. To improve the quality of the soil, zeolite is used. In its utilization, zeolite is able to withstand high heat and can increase the bearing capacity of clay soil. This research was conducted to determine the effect of zeolite addition on the compressive strength value of clay soil. In this study, the percentage of zeolite mixture used was 0%, 2%, 4%, 6%, 8%, and 10%. Based on the research results, the addition of zeolite mixture percentage in clay soil can increase the compressive strength value of the soil where the compressive strength value of the soil increases. However, the increase in soil compressive strength value occurred only until the addition of zeolite by 8% with a compressive strength value of 12.208 kg/cm2. At the time, at the addition of zeolite at 10%, the compressive strength value of the soil decreased to 9.928kg/cm2. Thus, the addition of zeolite can increase the compressive strength value of soil at the maximum addition limit of 8%. So, zeolite can be used as an alternative material for soil stabilization for subgrade layers. Keywords: Clay, Stabilization, Zeolite, Soil compressive strength

Enhancing Mechanical Properties of Low Plasticity Clay Soil Using Hemp Fibers: Effects of Fiber Content and Fiber Surface Coating

Enhancing Mechanical Properties of Low Plasticity Clay Soil Using Hemp Fibers: Effects of Fiber Content and Fiber Surface Coating

Research on key technology of cement mixing plie on clay layer with high plasticity index

Cement mixing pile is one of the common methods for road embankment foundation reinforcement, which can improve the bearing capacity, reduce the post-construction settlement caused by embankment loading, and increase the overall stability of embankment. In this paper, through field tests, lab tests and theoretical analysis, the factors affecting the quality of cement mixing piles in deep high plasticity clay soil are analyzed and the results of field tests and lab tests are compared, and finally the key construction parameters and relevant pile strength data in deep marine clay soil area are derived for similar projects.

Effect of randomly distributed polypropylene fibers on unconfined compressive strength, shear strength, and compressibility characteristics of Algerian high plasticity clay soil

Effect of randomly distributed polypropylene fibers on unconfined compressive strength, shear strength, and compressibility characteristics of Algerian high plasticity clay soil

Enhancement of clay-concrete interface strength through applying cycles of heating and cooling

This research studied the effect of heating and cooling cycles on the interface strength of saturated low plasticity clay soil (with a plasticity index of 12) in contact with concrete and the potential for using heating to increase pile capacity. A modified direct shear test device with clay specimen dimensions of 300 × 300 × 200 mm, featuring a concrete block at the bottom, was used for the tests. The heating system used heating rods to warm circulating water, which in turn heated the specimens. Four tests were conducted without heating-cooling cycles at ∼ 20 °C at effective normal stress of 30, 69, 110, and 150 kPa. Specimens subjected to effective normal stresses of 69, 110, and 150 kPa were tested under one heating cooling cycle up to 40, 55, and 70 °C, while the specimen under 30 kPa underwent only one heating-cooling cycle up to 70 °C. Additional tests were performed on specimens under 110 kPa with 4 heating-cooling cycles up to 40 °C, 4 heating-cooling cycles up to 55 °C, and 4 heating-cooling cycles up to 70 °C, as well as 9 heating-cooling cycles up to 55 °C. The results showed a significant increase in peak and post-peak interface friction angles by a range of 5.4% to 43.2%. The thermally induced volumetric strain due to contraction (TIVS) increased with increasing target temperature, but remained constant regardless of changes in applied effective normal stress.

Determination of shear strength parameters of compacted high plasticity clay soils based on different laboratory tests

In civil engineering projects, soils are compacted to improve their engineering behavior and properties. Compacted soils are widely used in dams, embankments and road infrastructure. Compacted fine-grained soils, especially clay-containing soils, are frequently used as barriers to water and pollutant movement in landfills. Shear strength parameters of compacted high plasticity clay soils depend on many variables such as consistency limits, dry density, and degree of saturation. In this study, 20 high plasticity clay soil samples were used and geotechnical identification tests were performed on each of them. Direct shear box and unconfined compression tests were carried out to determine the shear strength parameters of the samples prepared by compression in their compaction characteristics. As a result of this study, the relationships between the geotechnical properties of soil samples and both the effective shear strength parameters and total shear stress parameters were evaluated.

The Effect of Curing Time and Temperature Change on Strength in High Plasticity Clay Soils Reinforced with Waste Egg Shell Powder

The Effect of Curing Time and Temperature Change on Strength in High Plasticity Clay Soils Reinforced with Waste Egg Shell Powder

Perubahan Plastisitas dan Permaebilitas Tanah Lempung (CH) terhadap Penambahan Semen dan Limbah BAFA

High Plasticity Clay (CH) soils have poor material characteristics, such as large shrinkage which results in high plasticity so that soil improvement is required using cement and coal waste is added (bottom ash and fly ash). The purpose of adding the mixture is to see its effect on changes in the properties of soil plasticity and permeability. BAFA variation is 4%, 8%, 12% and 16%, cement variation is 3% and 5%. Atterberg limit and soil permeability testing is carried out on ripening day 0.7 and 28 days. The test results show changes in the value of Plasticity Index (Plasticity Index) or the value of PI and the value of k (constant) in the soil permeability test that has been added to the mixed material. Based on the results of the atterberg limit test, there was a decrease in the value of the soil plasticity index (PI) and the liquid limit value (LL) while the plastic limit (PL) experienced an increase in value along with the increase in cement content and BAFA waste, while in the soil permeability test it was known that the original soil sample was more difficult to penetrate water compared to soil samples that have been mixed with cement and BAFA waste.

Mechanical Behavior of Low Plasticity Clay Soil Stabilized with Rice Husk Ash

There is much research on how the addition of rice husk ash (RHA) and lime improves the mechanical behavior of the soil, particularly in clayey soils. RHA is a waste material and polluting for the environment; Therefore, its use can be considered as an economic and ecological alternative. The main objective of this analysis is to determine the influence of rice husk ash (RHA) to stabilize this type of soil. This research is based on the development of an alternative method for the improvement of low plasticity clay soils using an agricultural residue such as rice husk ash and lime for use in civil works. Soil mixtures with rice husk ash were made in different percentages to evaluate its geotechnical behavior as a stabilizer. Laboratory tests like OMC, MDD tend to increase when RHA is added. Shear strength increased as ash was added, where it reached a higher value with the addition of 40% RHA, increasing from 197.70 kPa to 323.00 kPa. Finally, the results obtained show an improvement due to the presence of RHA, however, the investigation is still in process to determine if the addition of higher RHA continues to improve or decrease its shear stress.

Hybridization of Differential Evolution and Adaptive-NetworkBased Fuzzy Inference System in Estimation of Compression Coefficient of Plastic Clay Soil

One of the important geotechnical parameters required for designing of the civil engineering structure is the compressibility of the soil. In this study, the main purpose is to develop a novel hybrid Machine Learning (ML) model (ANFIS-DE), which used Differential Evolution (DE) algorithm to optimize the predictive capability of Adaptive-Network-based Fuzzy Inference System (ANFIS), for estimating soil Compression coefficient (Cc) from other geotechnical parameters namely Water Content, Void Ratio, Specific Gravity, Liquid Limit, Plastic Limit, Clay content and Depth of Soil Samples. Validation of the predictive capability of the novel model was carried out using statistical indices: Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Correlation Coefficient (R). In addition, two popular ML models namely Reduced Error Pruning Trees (REPTree) and Decision Stump (Dstump) were used for comparison. Results showed that the performance of the novel model ANFIS-DE is the best (R = 0.825, MAE = 0.064 and RMSE = 0.094) in comparison to other models such as REPTree (R = 0.7802, MAE = 0.068 and RMSE = 0.0988) and Dstump (R = 0.7325, MAE = 0.0785 and RMSE = 0.1036). Therefore, the ANFIS-DE model can be used as a promising tool for the correct and quick estimation of the soil Cc, which can be employed in the design and construction of civil engineering structures.

Use of Cone Penetration Test for Classification of Some Sudanese Soils; the State of the Art

The cone penetration test (CPT) method has successfully been applied in Sudan for research, foundation design and the solution of geotechnical problems for various engineering structures since 1977. Based on analyses of database accumulated during four decades correlation relationships have been developed to classify local soils from CPT data. This paper presents the state of the art and the main findings of previous studies carried out on the application of CPT for soil classification. A simple and reliable CPT method based on the statistical “discriminant analysis” technique was proposed in 1980 to classify a given soil of known CPT parameters into one of four main USCS soil groups. Another correlation was proposed in a different study between CPT data andrelative consistency of highly plastic clay soils. The original soil classification method was further modified in 2003 to include more database and incorporate additional features relating to the consistency of clay soils and relative density of sandy soils. The accuracy of the CPT based soil classification method was examined amongst worldwide known methods by comparison of the soil types predicted from CPT and the actual soil profiles. The comparison study showed that the method performed quite well in classifying alluvial soils which are similar to those used in their development.

SHEAR STRENGTH BEHAVIOUR OF REMOULDED FINE-GRAINED SOILS TREATED WITH HYDRATED LIME

This paper presents an experimental study to assess the effect of lime treatment on the shear strength of low plastic clay and silt soils. The triaxial and direct shear tests determined the total and effective shear strengths for soil samples of the CL and ML soil groups prepared in their natural state and after treatment with 2% and 4% hydrated lime. The test specimens were initially compacted at their standard Proctor OMC and MDD conditions and allowed to cure before being tested. The study showed that the addition of lime significantly affected the basic properties of the soil types by modifying their gradation, rendering them non-plastic, and changing their OMC and MDD values. The lime treatment produced positive results by improving the total and effective soil strengths; however, the two study soils responded differently. Significant shear strength improvements were achieved in the lime-treated CL soil, but generally, the effect was relatively small for the ML soil. The gain in soil strength due to lime addition may be attributed to the clay particles flocculation and aggregation, increasing the adequate grain size, thus improving the soil matrix strength. In general, the addition of hydrated lime produced increases in the soil cohesion and reductions in the angle of internal friction; however, the effects are more pronounced in the CL than in the ML soil. Different effective strength parameters were revealed from the CU and DS test methods. The former tended to give higher cohesion and lower friction angles compared to the latter.

Improved Shear Strength Performance of Compacted Rubberized Clays Treated with Sodium Alginate Biopolymer.

This study examines the potential use of sodium alginate (SA) biopolymer as an environmentally sustainable agent for the stabilization of rubberized soil blends prepared using a high plasticity clay soil and tire-derived ground rubber (GR). The experimental program consisted of uniaxial compression and scanning electron microscopy (SEM) tests; the former was performed on three soil-GR blends (with GR-to-soil mass ratios of 0%, 5% and 10%) compacted (and cured for 1, 4, 7 and 14 d) employing distilled water and three SA solutions—prepared at SA-to-water (mass-to-volume) dosage ratios of 5, 10 and 15 g/L—as the compaction liquid. For any given GR content, the greater the SA dosage and/or the longer the curing duration, the higher the uniaxial compressive strength (UCS), with only minor added benefits beyond seven days of curing. This behavior was attributed to the formation and propagation of so-called “cationic bridges” (developed as a result of a “Ca2+/Mg2+ ⟷ Na+ cation exchange/substitution” process among the clay and SA components) between adjacent clay surfaces over time, inducing flocculation of the clay particles. This clay amending mechanism was further verified by means of representative SEM images. Finally, the addition of (and content increase in) GR—which translates to partially replacing the soil clay content with GR particles and hence reducing the number of available attraction sites for the SA molecules to form additional cationic bridges—was found to moderately offset the efficiency of SA treatment.

Experimental Study on the Mechanical Behavior of Cemented Soil Reinforced with Straw Fiber

An experimental program was conducted to evaluate the effect of straw fibers and cement percents on the mechanical properties of low plasticity clay soil. This research work aimed to assess if the straw fibers addition can enhance the strength properties of untreated and cement treated soil. Further, a few numbers of researches have been done on using straw fibers in reinforcing clay soils. In the present study, four percent; based on the dry weight of soil; of straw fibers (0.25, 0.5, 1.0 and 1.5%) and three percent of cement (2, 4 and 6%) were used. All soil samples (untreated and cement treated samples) were prepared at optimum moisture content (OMC) and maximum dry unit weight (γdmax) of natural soil. The cemented un-reinforced and fiber-reinforced samples were cured for different curing periods (varied between 3 to 90 days) at 20 °C. Different tests including unconfined compression, P-wave velocity, water absorption capacity (WAC) of straw fiber, electrical conductivity, pH and scanning electron microscopy tests were investigated. The test results show that the strength behavior of soil samples depends considerably on the percents of both straw fibers and cement. The increase in the unconfined compressive strength (UCS) is most apparent in the un-cemented and cemented soil samples having 0.5% straw fibers percent. While this increase in the UCS is linear with increasing cement percent (i.e. as cement percent increase the UCS increased). Further, the contribution of both straw fibers and cement percents in the increasing the UCS is much more than the increase caused by them individually. The stress–strain behavior of soil samples changes from brittle behavior to ductile one with straw fiber addition.

Effects of fly ash column treatment of HP clayey soils on seismic behavior of R/C structures

The behavior of soil directly affects not only its stability condition but also structural response of structural systems. High-plasticity clay soil (CH) is vulnerable to volumetric swelling leading to different settlements in structural systems. Hence, it becomes indispensable to propose practical solutions to reducing this effect. In the present study, structural response of R/C frame buildings, resting on high plasticity clayey soils strengthened through the coal fly ash column technique, to earthquake motion is investigated. For this aim, the swelling behavior of high plasticity clay soil (CH) is identified with in-situ experimental tests on the regions with high swelling potential in the city of Kirikkale, Turkey. In order to reduce the swelling potential of the investigated regions, the coal fly ash column technique was implemented to the reference soil specimen with high swelling percentage of 15.6%. Experimental results obtained from the strengthened soil specimens were compared to those from the reference specimen. This comparison revealed that the coal fly ash column approach has a considerable effect on improving the swelling behavior of the high plasticity clay soil. The decrease in the volumetric swelling value is also thought to directly improve the response of a building structure settled on high plasticity clay soil. The improvement in the seismic response of existing R/C structures located in the regions with high swelling potential was identified by adopting the increased allowable bearing pressure value of the improved soil in the analyses. Based on the comparative study, structural earthquake response of R/C frame systems was investigated on the basis of the engineering parameters, including the base-shear force, base overturning moment, base axial force and settlement of foundation. The percent changes in these values showed that the base axial force and settlement of foundation were improved with the help of this strengthening application.