Engineering Properties Of Clay Soil Research Articles

Engineering properties of clay soil stabilised with glass powder and rubber particles – a comparative study

ABSTRACT Soil improvement is a significant aspect of geotechnical engineering that requires periodic assessment and modification. This study aims to see how glass powder (GP) and rubber particles (RP) affect the shear strength and bearing capacity of clay soil collectively and separately. The soil samples were subjected to direct shear testing and California Bearing Ratio (CBR) tests at various glass powder and rubber particle contents. The CBR test was conducted under soaked and unsoaked conditions. Clay-rubber, clay-glass powder, and clay-rubber-glass powder mixtures were prepared for the tests. It was discovered that adding glass powder and rubber particles improved the soil’s shear strength parameters and bearing capacity. A comparative analysis was conducted on the clay-rubber mixtures and clay-glass powder mixtures. The results indicated much improvement by the rubber particles than the waste glass powder in the direct shear test. In contrast, the glass powder had a better impact than the rubber particles in the CBR test. Furthermore, a correlation analysis was conducted to ascertain the relationship between the CBR values and the shear strength of the soil samples using a single Linear Regression Analysis (SRLA) model. The correlation yielded satisfactory coefficients (R2), indicating a strong link between the engineering properties.

Strength Behaviour of Clay Soil Stabilized With Lime

Geotechnical Engineers are searching for new sustainable material, which can be suitable and effectively used to improves the engineering properties of clay soil. In this research lime is used as stabilizing material in the variable percentage of 1%,3%,5%,7%,9%,10%,12% and 15%. Lime is used as the admixture for soil stabilisation. Swelling pressure of the soil mixed with various proportions of lime such as 1, 7, 12 and 15%. Unconfined compression test, Plastic limit, Liquid limit, standard compaction proctor test, free swell index test and one-dimensional consolidation test are conducted to evaluate the clay soil strength in the laboratory. The experimental investigation results show that maximum strength improvement was achieved in the 12% lime mixed with clay soil and the strength improvement in the range of 300kPa. The results of the swelling test showed that applying lime to the soil decreases the swelling nature of clay soils.

A study of calcium hydroxide as a stabilizing agent in clay soil toward California bearing ratio and unconfined compression value

Soil is one of the most important materials in construction. Soil stabilization is an attempt to increase condition of soil that have poor engineering properties. Soil stabilization is also a mixture of soil with certain stabilizing agents to increase the engineering properties of the soil to attain technical requirements. This research used calcium hydroxide as a stabilizing material. The study purposes were to improve the engineering properties of clay due to the addition of 3% - 30% calcium hydroxide, Ca(OH)2. The clay soil was classified as A-7-6 (9) based on the AASHTO classification system and was classified as CL (Clay – Low Plasticity) based on USCS. The unsoaked California Bearing Ratio (CBR)of original soil was 6.29%. Meanwhile, the Unconfined Compression Test (UCT) of original soil was 1.42 kg/cm2. The study showed that the addition of calcium hydroxide increased the engineering properties of clay soil. The unsoaked CBR reached the maximum value of 11.46% at a variation of 12% calcium carbonate. The UCT also gained the maximum value of 3.12kg/cm2 at a variation of 12% calcium hydroxide.

Engineering Properties of Clay Soil Stabilized with Tiles Particles

Engineering Properties of Clay Soil Stabilized with Tiles Particles

A Preliminary Study on the Engineering Properties of Clay Soil

Karl Von Terzaghi, the father of soil mechanics, says, “There is no other soil which is as problematic as clay soil”. In many places across the badlands of Alberta, clay soil is known to be troublesome and cause issues with buildings and infrastructure. Climate conditions, erosion and weathering can cause the unstable clay soil to create landslides, which consequently damage many of these structures. For this reason, engineers are sent to these sites to monitor and collect data over a period of time to compare and contrast their results. The purpose of this study is to learn and understand the properties of clay soils through different classification and index tests. Two clay soils, kaolinite and bentonite, were tested for their properties and their results were compared. Some of the tests performed include the hydrometer analysis, pycnometer analysis, and atterberg limits. The hydrometer analysis is the process in determining the size of silts and clays (when sieves cannot be used). The pycnometer analysis is used to determine the specific gravity of a substance. Atterberg limits are used to determine the water content at which a soil starts to shift from liquid, plastic or semi-solid. These tests were done in two different solutions - one containing distilled water and one with saline water - to understand the effect of the solution on the liquid and plastic limits. The goal of this study was achieved and the results can be used to understand more about the engineering properties of clay soils and apply these studies to future field work. By understanding these properties, further research can be done to discover long term solutions to landslides caused by the problematic soil.

Multiscale study of the influence of promoters on low-plasticity clay stabilized with cement-based composites

Abstract This study presents the results of the utilization of a cement-based composite stabilizer on soil modification. The effects of additives, including NaOH, CaCl2, Na2SiO3, NaOH/CaCl2 and Triethanolamine, on the engineering properties of clay soil were investigated and evaluated. A series of laboratory tests, including unconfined compressive strength, Atterberg limits, pH, conductivity, XRD, and SEM, were performed. An improvement in the unconfined compressive strength and elastic modulus of the soil, depending on the type and content of additives, was observed. It was found that the cement-based stabilizer supplemented with 1.5% NaOH/CaCl2 could produce more CSH and effectively bond soil particles together, resulting in the most favorable engineering properties. This conclusion was also confirmed by the XRD and SEM results, which showed that the porosity of this sample was lower and that it had a much denser structure than those of the other samples. The strength of the composite stabilizer was 20% higher than that of the soil stabilized with cement. The stress-strain curves of the samples indicated that the failure behavior was almost brittle, except for the samples with 1.0%, 1.2%, and 1.5% NaOH. The addition of 1.0%, 1.2%, and 1.5% NaOH resulted in strain-hardening behavior, while the other samples presented strain-softening behavior. In addition, the most appropriate replacement rate of silica fume was selected by changing the substitution rate while the total dry weight of the cement-silica fume mixtures remained unchanged. This investigation suggested that the optimum substitution rate of the silica fume was 40%. The stabilization mechanism of a cement-based composite stabilizer was analyzed using XRD and SEM.

Effect of Addition of Coarse Sand Particles on Engineering Properties of Clay Soil

Effect of Addition of Coarse Sand Particles on Engineering Properties of Clay Soil

Effect of by-product steel slag on the engineering properties of clay soils

Clay soils, mainly if they contain swelling minerals such as smectite or illite, may cause severe damage to structures, especially when these soils are subjected to wetting and drying conditions. High expansion and reduction in shear strength and foundation bearing capacity will take place due to the increase in water content of these soils. The engineering properties of these kinds of soils can be improved by using additives and chemical stabilizers. In this work, by-product steel slag was used to improve the engineering properties of clay soils. Lab and field experimental programs were developed to investigate the effect of adding different percentages of steel slag on plasticity, swelling, compressibility, shear strength, compaction, and California bearing ratio (CBR) of the treated materials. The results of tests on the clay soil showed that as steel slag content increased, the soil dry density, plasticity, swelling potential, and cohesion intercept decreased and the angle of internal friction increased. For the CBR, the results of the tests showed an increase in the CBR value with the increase in slag content.

The effect of magnesium chloride solution on the engineering properties of clay soil with expansive and dispersive characteristics

Because expansive and dispersive soils damage engineering structures, extensive studies on using additives to ameliorate the effects of these soils have been conducted. In this study, the effect of magnesium chloride (MgCl2) solution on the engineering properties of clay soils was evaluated. Previous studies on this subject have shown that MgCl2 is more commonly used as an anti-icing agent on roads than as a soil stabilizer. MgCl2 is also used to control dust and humidity on roads and to reduce the scattering of coarse particles from road surfaces. However, as the use of MgCl2 becomes more common, its potential to improve the geotechnical properties of problematic soils will receive increasing attention.To this end, the variation in the engineering properties of expansive and dispersive clay soil samples as functions of the added MgCl2 content was investigated. First, the physical and chemical properties of the soil sample were determined. Next, the swell percentage, swell pressure, crumb, pinhole and unconsolidated undrained (UU) triaxial compression tests were performed at different curing times on samples with and without the additive by compressing the sample to achieve particular compaction characteristics. Scanning electron microscopy (SEM) analyses were performed to observe the microstructures in the sample without the additive and with the amount of additive that most strongly improved the expansive and dispersive qualities of the clay. The results show that dispersive and expansive clay soils can be effectively improved using an additive MgCl2 solution.

Mechanical properties of weakly bonded cement stabilized kaolin

Soil mixing with cement is one of the fastest growing specialties in many coastal and offshore areas and is becoming means of improving poor ground conditions. The engineering properties of clay soils can be enhanced by addition of cement, thereby producing an improved construction material. While this ground improvement technique is gaining popularity, the strength-deformation behaviour over the long term and the soil structure of the clay-cement mixture are not well understood. This paper aims to investigate the mechanical behaviour of cement-stabilized Kaolin with Portland cement. An extensive laboratory program was carried out to determine the mechanical characteristics of kaolin-cement, with some brief examination of the effects of curing environment. Results show that while cement increases strength, it also reduces axial strain required to achieve failure under drained conditions. Furthermore, when the cement content is 5 percent or less, kaolin-cement may not improve with time after 28 to 56 days; this may be partially due to softening during curing. Addition of cement increases the degree of flocculation of the clay particles; this is associated with an increase in pH of the pore wate However, the pH decreases over time. The formation of various new reaction products has been identified using scanning electron microscopy (SEM) technique.

Effectiveness of Portland Cement and Lime in Stabilizing Clay Soils

Pavement subgrades constructed with clay soils can cause significant pavement distress because of moisture-induced volume changes and low subgrade support values. Lime is well known for its ability to stabilize plastic clays; however, portland cement also provides highly effective clay stabilization, usually with the added benefit of higher strength gain. Stabilizing clays with cement or lime can improve subgrade properties at a lower cost than either removing and replacing material or increasing the base thickness to reduce subgrade stress. The clay soil stabilization mechanism for the calcium-based stabilizers portland cement and lime is reviewed. These materials modify soil properties through cation exchange, flocculation and agglomeration, and pozzolanic reaction. Additionally, cement provides hydration products, which increase the strength and support values of the subgrade materials as well as enhance the permanence of the treatment. Comparative laboratory and field performance studies by others, focusing on stabilization of clay soils with portland cement or lime, are critically reviewed. Several factors affecting stabilization are discussed, including stabilizer test procedures, dosage effects to soil properties, mixing, compaction, and gradation and pulverization. Additionally, durability of cement and lime as stabilizers is reviewed, including wetting and drying, freezing and thawing, leaching, and long-term field performance. The research reviewed indicates that, if proportioned and applied properly, both cement and lime can effectively improve the engineering properties of clay soils over the life of a pavement. The results presented provide a guide to the engineer about the property changes to expect when using portland cement and lime with regard to volume stability, strength, and durability.

Influence of liquid limit and slaking on cement stabilized clayey admixtures

Clayey soils, especially clayey soils with high or very high liquid limits (> 60%) often present difficulties in construction operations because they usually contain expansive clay minerals. However, the engineering properties of clay soils can be enhanced by the addition of either cement or lime, thereby producing an improved construction material. In this research, slake durability was related to the liquid limit and unconfined compressive strength of clayey admixtures. Three of the most important components in clay soils, namely, kaolinite, montmorillonite and quartz, were combined to make the clayey admixtures. A slaking value of 45% is suggested as identifying satisfactory stabilization. For clayey admixtures with liquid limit between 40% and 60%, this could be achieved with the addition of between 4% and 12% cement. Clayey admixtures with liquid limits over 60% could only achieve this with large uneconomical amounts of cement (> 12%).

The importance of pore water chemistry on mechanical and engineering properties of clay soils

The classical Coulomb-Terzaghi shear strength equation, (cr— tan depends not only upon mechanical and mineralogical factors, but to a high degree upon the total chemistry of the system. Changes in chemistry owing to natural and anthropogenic factors may change the strength properties of a given clay soil at a given water content. The classical example of slow acting chemical changes is the development of quick clay properties. Modern infiltration of different electrolytes and detergents from leaking sewer systems may change shear strength and compressibility of the ground. These processes are different in clays of expanding and nonexpanding minerals. The importance of the different cation species seems to depend upon valency and polarizability. Influence of anions is more complicated and depends upon interaction with edge charges and the crystalline properties of the clay minerals.

Engineering Properties of Clay Soils

Engineering Properties of Clay Soils