Swell Behavior of Expansive Soils with Stabilized Fly Ash Columns

2018 ◽  
pp. 399-406
Author(s):  
F. Darikandeh ◽  
B. V. S. Viswanadham
Keyword(s):  
Fly Ash ◽  
Expansive Soils

Behavior of expansive soils stabilized with fly ash

2008 ◽  
Vol 47 (3) ◽  
pp. 509-523 ◽  
Author(s):  
Fusheng Zha ◽  
Songyu Liu ◽  
Yanjun Du ◽  
Kerui Cui
Keyword(s):  
Fly Ash ◽  
Expansive Soils

Effect of Fly Ash on the Behavior of Expansive Soils: Microscopic Analysis

2013 ◽  
Vol 19 (1) ◽  
pp. 85-94 ◽  
Author(s):  
B. LIN ◽  
A. B. CERATO ◽  
A. S. MADDEN ◽  
M. E. ELWOOD MADDEN
Keyword(s):  
Fly Ash ◽  
Expansive Soils ◽  
Microscopic Analysis

Evolution of thermal and mechanical properties of mine tailings and fly ash mixtures during curing period

2014 ◽  
Vol 51 (5) ◽  
pp. 570-582 ◽  
Author(s):  
Joon Kyu Lee ◽  
Julie Q. Shang
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Fly Ash ◽  
Mine Tailings ◽  
Mechanical Characteristics ◽  
Early Stage ◽  
Expansive Soils ◽  
Thermal And Mechanical Properties ◽  
Curing Period ◽  
Compaction Energy

Fly ash is often used as a binder for modifying the properties of geomaterials, such as organic and expansive soils, sludge from water treatment, dredged sediments, mine tailings, etc. Changes in thermal and mechanical properties of compacted mixtures of mine tailings and fly ash are studied over a curing period of 120 h. The study includes the measurement of thermal conductivity, temperature, unconfined compressive strength, and elastic modulus. Effects of the amount of fly ash added to mine tailings, molding water content, and compaction energy on these properties are investigated. Pore-size distribution and surface texture are analyzed to characterize the microstructures of fly ash treated–mine tailings. Relationships between the thermal conductivity and properties that capture packing and mechanical characteristics of mine tailings and fly ash mixtures are established. These observations provide enhanced understanding of thermal, mechanical, and structural properties of fly ash–treated mine tailings, which is associated with the hydration process at the early stage of the mixtures.

scholarly journals Study on Physical-Mechanical Properties and Microstructure of Expansive Soil Stabilized with Fly Ash and Lime

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Sheng-quan Zhou ◽  
Da-wei Zhou ◽  
Yong-fei Zhang ◽  
Wei-jian Wang
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Physical Parameters ◽  
Swelling Ratio ◽  
Sem Images ◽  
Mixture Ratio ◽  
Plain Area ◽  
Stabilized Soil

Fly ash and lime have been frequently employed to reduce the swelling potential of expansive soils. Laboratory experiments, scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used in this study to investigate the stabilizing effect of fly ash and lime on expansive soils in the Jianghuai undulating plain area. The comparison was drawn between the variation laws of physical parameters, mechanical properties, microstructure, and mineral composition of expansive soil before and after being stabilized. Experimental results suggest that, after 5% lime is added based on fly ash, the plasticity index of the expansive soil decreases by 64.9%, the free swelling ratio is reduced to about 10%, the unloading swelling ratio is reduced to nearly 4%, and the stabilized soil no longer exhibits the expansive property. The unconfined compressive and tensile strengths of the stabilized soil increase first and then decrease with the rising in fly ash content. After the addition of 5% lime, both the unconfined compressive and tensile strengths increase significantly. The optimum modifier mixture ratio is obtained as 10% fly ash + 5% lime. The SEM images reveal that the microstructures of the stabilized expansive soil vary from an irregular flake-like and flocculent structures to blocky structures, and the soil samples compactness is enhanced. XRD results indicate that quartz is the main component of the stabilized soil. These are the underlying causes of the rise in the strength. The conclusions of this study can be referenced for the engineering design and construction of expansive soil in Jianghuai undulating plain area.

scholarly journals Undrained Strength Characteristics of Fibre Reinforced Expansive Soils

2021 ◽  
Author(s):  
G. Surya Narayana Kurup ◽  
Sona P. S. ◽  
Luthfa U ◽  
Varsha Manu ◽  
Amal Azad Sahib
Keyword(s):  
Fly Ash ◽  
Expansive Soils ◽  
Uttar Pradesh ◽  
Strength Characteristics ◽  
Fibre Reinforcement ◽  
Polypropylene Fibres ◽  
Swell Index ◽  
Swell Potential ◽  
Granular Pile ◽  
Deccan Plateau

Expansive soils are those whose volume changes take place while it comes in contact with water. It expands during rainy season due to intake of water and shrinks during summer season. Expansive soils owe their characteristics due to the presence of swelling clay minerals. Expansive soils cover nearly 20% of landmass in India and include almost the entire Deccan plateau, western Madhya Pradesh, parts of Gujarat, Uttar Pradesh, Andhra Pradesh, Karnataka and Maharashtra. The properties that describe the expansive behaviour of soils are free swell index, swell potential and swell pressure. This behaviour has an impounding effect on the bearing capacity and strength of foundation lying on such a soil. Some of the stabilization techniques which are currently being used are physical alternations, sand cushioning, belled piers, under reamed piers, granular pile anchors, chemical stabilization, and fibre reinforcement techniques. This paper focuses on improvement in the strength characteristics of stabilized Chittur soil. The commonly used stabilizer for expansive soils is lime. This paper looks upon alternative materials such as fly ash and polypropylene fibres in order to reduce the lime content. It was concluded from the trials that an optimum combination of 1.5% lime, 10% fly ash and 0.2% polypropylene fibres contribut

scholarly journals Resilient performance of expansive subgrades stabilized with nanosized and activated fly ash

2021 ◽  
Author(s):  
Frank Ikechukwu Aneke ◽  
Mohamed Mostafa Hassan
Keyword(s):  
Fly Ash ◽  
Resilient Modulus ◽  
Morphological Changes ◽  
Expansive Soils ◽  
Pozzolanic Reaction ◽  
Exchange Capacity ◽  
Degree Of Saturation ◽  
Strength Development ◽  
High Plasticity ◽  
Test Result

Subgrades across arid and semi-arid region are known for its random swelling, with high plasticity due to moisture infiltration of the pavement structures. Subgrades materials are significantly influenced by the cahnges in degree of saturation, which is unavoidable. Studies in the past, have reported several positive results on the stabilization of expansive soils with additives like lime, cement, fly ash, etc. In this study, resilient performance of expansive subgrades treated with 0.5%, 1.0%, 1.5% and 2.0% of nanosized and activated fly ash (NFA and AFA) is presented. Series of cation exchange capacity tests, zero swelling tests (ZST) and resilient modulus (M_R ) tests were performed to study the effects of NFA and AFA on resilient modulus (M_R) and swelling index of the subgrades material respectively. Scanning electron microscopy (SEM) tests was conducted to evaluate the morphological changes in the subgrades, and compounds responsible for resilient strength development. The result showed that, NFA and AFA inclusions in the treatment of expansive subgrades caused an increase in resilient strength and decrease in swelling stress to a limiting stabilizer content of 0.5% and 1.0% beyond which, the resilient modulus values increased triggering a significant decrease in swelling stress. The test result revealed that the reduction was caused by the pozzolanic reaction between the stabilizers and available moisture required for full completion of pozzolanic process. Based on the test result, nano-fly ash exhibite high potential in improving resilient strength and reducing swelling stress to 58.7% and 63% respectively on the average compared to activated fly ash. This study suggest a feasible solution to improve the quality and performance of expansive subgrades.

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