scholarly journals An Experimental Study on the Geotechnical, Mineralogical, and Swelling Behavior of KPK Expansive Soils

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bakht Zamin ◽  
Hassan Nasir ◽  
Khalid Mehmood ◽  
Qaiser Iqbal ◽  
Asim Farooq ◽  
...  
Keyword(s):  
Expansive Soils ◽  
Clay Fraction ◽  
Expansive Soil ◽  
Vital Role ◽  
Maintenance Cost ◽  
High Plasticity ◽  
Swell Potential ◽  
Overall Stability ◽  
Swelling Characteristics ◽  
Arid And Semiarid

Expansive soils are found in numerous regions of the world explicitly in arid and semiarid zones. These soils expand when absorbed moisture and shrink when released water. Such soil is viewed as a characteristic risk for infrastructures due to the shrink and swell behavior. These soils become more problematic when lightly or moderately loaded structures are built on them. The swelling and shrinkage in these soils chiefly happen due to the presence of montmorillonite minerals. The mineralogical and swell behavior of foundation soils is playing a vital role in the overall stability of a structure. These parameters are often ignored in the geotechnical report writing stage specifically in small projects, due to which, the durability and service life of the facilities are reduced and the maintenance cost is increased. To mitigate the potential damages in structures constructed on expansive soil, it is necessary to assess the mineralogical and swelling characteristics of expansive soil. The current study aims to determine the geotechnical, mineralogical, and swell behavior of the local expansive soils. Based on the results, the Karak soil has the highest plasticity index (PI) of 37% with a clay fraction of 28%, while the D.I. Khan soil has the least PI of 23% with a clay fraction of 17%. Similarly, Karak’s soil contained a higher percentage of montmorillonite (Rp = 8.9%). The maximum values of swell pressure, swell potential, and 1D deformation are 280 kPa, 12.5%, and 1.92 mm for the Karak soil, 6.45% 150 kPa, and 1.38 mm for D.I. Khan soil, and 10.5%, 245 kPa, and 1.64 mm for Kohat soil, respectively. This concludes that Karak’s soil has high plasticity and swell characteristics than Kohat and D.I. Khan soil. The swell characteristic of expansive soils increases with the increase in the percentage of the fine specifically the clay fraction. Furthermore, the Karak soil is more critical than Kohat and D.I. khan soil for lightly loaded structures.

scholarly journals Effect of Compaction Energy on Engineering Properties of Expansive Soil

2017 ◽  
Vol 3 (8) ◽  
pp. 610 ◽  
Author(s):  
Sadam Hussain
Keyword(s):  
Expansive Soils ◽  
Energy Levels ◽  
Expansive Soil ◽  
Substantial Improvement ◽  
Engineering Properties ◽  
Engineering Structures ◽  
Expansive Clays ◽  
Swell Potential ◽  
Compaction Energy ◽  
Strength And Deformation

Swelling of expansive clays is one of the great hazards, a foundation engineer encounters. Each year expansive soils cause severe damage to residences, buildings, highways, pipelines, and other civil engineering structures. Strength and deformation parameters of soils are normally related to soil type and moisture. However, surprisingly limited focus has been directed to the compaction energy applied to the soil. Study presented herein is proposed to examine the effect of varying compaction energy of the engineering properties i.e. compaction characteristics, unconfined compressive strength, California bearing ratio and swell percentage of soil. When compaction energy increased from 237 KJ/m3 to 1197 KJ/m3, MDD increased from 1.61 g/cm3 to 1.75 g/cm3, OMC reduced from 31.55 percent to 21.63 percent, UCS increased from 110.8 to 230.6 KPa, and CBR increased from mere 1 percent to 10.2 percent. Results indicate substantial improvement in these properties. So, compacting soil at higher compaction energy levels can provide an effective approach for stabilization of expansive soils up to a particular limit. But if the soil is compacted more than this limit, an increase in swell potential of soil is noticed due to the reduction in permeability of soil.

Analysis of a New Expansive Soils Stabilization Method Made from Eco-Cement and Fiber Reinforcement

2013 ◽  
Vol 649 ◽  
pp. 217-222
Author(s):  
Mircea Aniculaesi ◽  
Anghel Stanciu ◽  
Irina Lungu
Keyword(s):  
Portland Cement ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Fiber Reinforcement ◽  
Synthetic Fiber ◽  
Expansive Clay ◽  
Swelling Potential ◽  
Stabilization Method ◽  
Swell Potential ◽  
Main Factor

The main factor that governs the shrink-swell behavior of expansive soils is the change in water content and the amount and type of clay size in the soil. In this paper, the research made are focused in reducing the swell potential of the studied clay by improvement in two ways: first by stabilization with a combination of eco-cement and Portland cement (1:1 ratio), and second by synthetic fiber reinforcement. A series of laboratory tests were performed on synthetic fiber reinforced expansive soil to determine the potential for using synthetic fiber reinforcement to reduce swell potential of soils. Specimens tested were prepared at two different synthetic fiber dosages 0.2% and 0.4%. The treatment of expansive clay with 5% eco-cement and 5% Portland cement revealed a better improvement of the swelling potential. The synthetic fiber reinforcement of the expansive soil doesn’t lead to a significant improvement of the soil.

scholarly journals Swelling Curve in Terms of Effective Stress for Expansive Clays

2020 ◽  
Vol 195 ◽  
pp. 02023
Author(s):  
Rafael Baltodano-Goulding
Keyword(s):  
Effective Stress ◽  
Expansive Soils ◽  
Characteristic Curve ◽  
The State ◽  
Isomorphous Substitution ◽  
High Plasticity ◽  
Charge Imbalance ◽  
Swell Potential ◽  
Free Swell ◽  
A Charge

Expansive soils can present an unsaturated state where the soil exhibits volume changes due to both moisture variations that change the state of stresses and moisture variations that interact with its mineralogical characteristics. These special kinds of soils are normally clay type soils that had suffered isomorphous substitution creating a charge imbalance of the clay mineral crystals. This imbalance promotes the trapping of water molecules by the clay particles. It is commonly assumed that a high plasticity index can be an indication of a clay´s high swell potential. However, in arid regions, it is possible to have clays with very high swell potential and low plasticity indexes due primarily to a decrease in the state of effective stress, which will produce expansion of the material. It is common practice to study the swelling characteristics of these soils by performing free-swell tests that can be used for designing removal and replacement backfills or drilled shafts. However, the expansion percentage obtained from this type of test is actually in terms of total stresses and not in terms of effective stress, as it is commonly assumed. Moreover, it is highly dependent on the magnitude of the preload used. This paper presents some efforts made to obtain the swelling part of the curve in terms of effective stresses from the traditional free-swell test. It was hypothesized that the shape of this curve could either have the shape of the rebound curve from a saturated consolidation test or a shape similar to the soil-water characteristic curve.

scholarly journals Development of Some Novel Suction-Based Correlations for Swell Behavior of Expansive Soils

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bakht Zamin ◽  
Hassan Nasir ◽  
Khalid Mehmood ◽  
Qaiser Iqbal ◽  
M. Tariq Bashir ◽  
...  
Keyword(s):  
Pore Water Pressure ◽  
Expansive Soils ◽  
Water Pressure ◽  
Expansive Soil ◽  
Field Testing ◽  
Published Data ◽  
The Novel ◽  
Field Instrumentation ◽  
Swell Potential ◽  
Unsaturated Expansive Soils

Swelling and shrinkage are the two distinctive characteristics of expansive soils, and due to this behavior, these soils are considered a natural hazard for infrastructure. Many structures in different regions have been impaired due to the swell/shrink behavior of the expansive soil. Most of the severe distress is impeded because of the inherent suction (negative pore water pressure) present in expansive soils. Both suction and swelling parameters are greatly affected by the surrounding moisture content. Due to this feature of expansive soil, geotechnical engineers are interested in utilizing the suction-based correlations for the assessment of unsaturated expansive soils. The current investigation was carried out to develop novel correlations incorporating lab testing and field instrumentation. To fulfill the objectives, eight sites of the local expansive soil in Pakistan were selected for samples collection and field testing. Conventional odometer testing was conducted to measure the swell pressure (Sp) and swell potential (S) of the fabricated/remolded specimens. Gypsum block (G-block) sensors were additionally utilized for estimating the matric suction in the field. To expand the database, the previously published data of the same nature was also incorporated. Based on the results, the power form of the novel correlations (suction-based) is highly significant for estimating (Sp), while for swell potential, the logarithmic correlation with R2 = 0.6551 is more significant than other forms of correlations. The proposed suction-based correlation can be equally utilized for the estimation of field suction as well as for swell behavior of expansive soil having a plasticity index (PI) ≥ 22%.

scholarly journals Full Scale Modeling of Footing Supported on Expansive Soil using Concrete Pile Anchor Foundation (CPAF).

2020 ◽  
Vol 8 (6) ◽  
pp. 1859-1864
Keyword(s):  
Expansive Soils ◽  
Limit State ◽  
Expansive Soil ◽  
Site Investigation ◽  
Ultimate Limit State ◽  
Upward Movement ◽  
Scale Modeling ◽  
Concrete Pile ◽  
Swelling Characteristics ◽  
A Site

Buildings constructions over expansive soils are exposed to many problems and cracks. The most damaging issues occur due to differential heave displacements, which cause excessive deformations to the overlying structure up to and beyond its serviceability limit state and, in the worst cases, its ultimate limit state. A site investigation is performed for the study area at Tabuk University, Kingdom of Saudi Arabia. The geotechnical soil properties and swelling characteristics were determined. Visual observations of samples obtained from drilled boreholes at study area revealed reddish brown to grey thinly laminated weathered shale followed by shale formation, the subsurface formation is classified (CH) according to USCS. The research study is aimed at measuring the contact pressure at field and studying the efficiency of concrete pile anchor foundation (CPAF) system in reducing heave of footings constructed on expansive soil. In the field, two full scales reinforced concrete footings with and without concrete anchor piles were constructed on top of the expansive shale. After construction of field prototypes, the test area is wetted for 64 days. Monitoring of the footing movement indicated that the footing upward movement using CPAF system caused a 62% less than the footing constructed directly on expansive shale.

scholarly journals An Experimental Study on the Effect of Micro-Metakaolin on the Strength and Swelling Characteristics of Expansive Soils

2022 ◽  
Author(s):  
Mohamed Sakr ◽  
Waseim Azzam ◽  
Mohamed Meguid ◽  
Hebatalla Ghoneim
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Soil Conditions ◽  
Arid Areas ◽  
Continuous Increase ◽  
Swell Index ◽  
The World ◽  
Swelling Characteristics ◽  
The Government

Abstract Expansive soils are found in many parts of the world, especially in arid areas and dry weather regions. Urbanization and development of new cities around the world resulted in construction in areas of challenging subsurface soil conditions. For example, in the Middle East, the Government of Egypt is building several new cities to accommodate the continuous increase in the country’s population. Most of these new cities are located in areas underlain by expansive soils. In this study, a series of laboratory tests were carried out to investigate the effect of introducing micro-metakaolin into the matrix of an expansive soil to improve the swelling potential as a new stabilizing material. Test results showed that micro-metakaolin can considerably decrease the free swell index of the soil by 37% and 54% at micro-metakaolin content of 15% and 25%, respectively. In addition, the shear strength of the soil was found to also increase as a result of the introduction of the micro-metakaolin material. Adding 25% micro-metakaolin content reduced the swelling pressure of the soil by about 33%. The results suggest that the proposed method is efficient in stabilizing and improving the properties of expansive soils found in arid areas. This is important to control excessive swelling and prevent possible damage to the supported structures.

scholarly journals Strength, Hydraulic, and Microstructural Characteristics of Expansive Soils Incorporating Marble Dust and Rice Husk Ash

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Fazal E. Jalal ◽  
Sultani Mulk ◽  
Shazim Ali Memon ◽  
Babak Jamhiri ◽  
Ahsan Naseem
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Sensitivity Analyses ◽  
Waste Materials ◽  
Strength Development ◽  
High Plasticity ◽  
Preconsolidation Pressure ◽  
Marble Dust

Expansive/swell-shrink soils exhibit high plasticity and low strength, which lead to settlement and instability of lightly loaded structures. These problematic soils contain various swelling clay minerals that are unsuitable for engineering requirements. In an attempt to counter the treacherous damage of such soils in modern geotechnical engineering, efforts are underway to utilize environmentally friendly and sustainable waste materials as stabilizers. This study evaluates the strength and consolidation characteristics of expansive soils treated with marble dust (MD) and rice husk ash (RHA) through a multitude of laboratory tests, including consistency limits, compaction, uniaxial compression strength (UCS), and consolidation tests. By using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses, the effect of curing on UCS after 3, 7, 14, 28, 56, and 112 days was studied from the standpoint of microstructural changes. Also, the long-term strength development of treated soils was analyzed in terms of the interactive response of impacting factors with the assistance of a series of ANN-based sensitivity analyses. It is found from the results that the addition of MD and RHA lowered down the water holding capacity, thereby causing a reduction in soil plasticity (by 21% for MD and 14.5% for RHA) and optimum water content (by 2% for MD and increased by 6% for RHA) along with an increase in the UCS (for 8% MD from 97 kPa to 471 kPa and for 10% RHA from 211 kPa to 665 kPa, after 3 days and 112 days of curing, respectively). Moreover, from the oedometer test results, m v initially increased up to 6% dosage and then dropped with further increase in the preconsolidation pressure. Furthermore, the compression index dropped with an increase in the preconsolidation pressure and addition of MD/RHA, while the coefficient of permeability (k) of RHA stabilized soil was higher than that of MD-treated samples for almost all dosage levels. The formation of the fibrous cementitious compounds (C-S-H; C-A-H) increased at optimum additive dosage after 7 days and at higher curing periods. Hence, the use of 10% RHA and 12% MD as replacement of the expansive soil is recommended for higher efficacy. This research would be helpful in reducing the impacts created by the disposal of both expansive soil and industrial and agricultural waste materials.

scholarly journals Sustainability Benefits Assessment of Metakaolin-Based Geopolymer Treatment of High Plasticity Clay

2020 ◽  
Vol 12 (24) ◽  
pp. 10495
Author(s):  
Rinu Samuel ◽  
Anand J. Puppala ◽  
Miladin Radovic
Keyword(s):  
Volume Change ◽  
Expansive Soils ◽  
Expansive Soil ◽  
High Plasticity ◽  
Lime Treatment ◽  
Chemical Additives ◽  
Ambient Temperatures ◽  
New Class ◽  
Stiffness Characteristics ◽  
Strength And Stiffness

Expansive soils are prevalent world over and cause significant hazards and monetary losses due to infrastructure damages caused by their swelling and shrinking behavior. Expansive soils have been conventionally treated using chemical additives such as lime and cement, which are known to significantly improve their strength and volume-change properties. The production of lime and cement is one of the highest contributors of greenhouse gas emissions worldwide, because of their energy-intensive manufacturing processes. Hence, there is a pressing need for sustainable alternative chemical binders. Geopolymers are a relatively new class of aluminosilicate polymers that can be synthesized from industrial by-products at ambient temperatures. Geopolymer-treated soils are known to have comparable strength and stiffness characteristics of lime and cement-treated soils. This study evaluates the sustainability benefits of a metakaolin-based geopolymer treatment for an expansive soil and compares its results with lime treatment. Test results have shown that geopolymers have significantly improved strength, stiffness, and volume-change properties of expansive soils. Increased dosages and curing periods have resulted in further property enhancements. Swell and shrinkage studies also indicated reductions in these strains when compared to control conditions. The sustainability benefits of both geopolymer and lime treatment methods are evaluated using a framework that incorporates resource consumption, environmental, and socio-economic concerns. This study demonstrates geopolymer treatment of expansive soils as a more sustainable alternative for expansive soil treatments, primarily due to metakaolin source material. Overall results indicated that geopolymers can be viable additives or co-additives for chemical stabilization of problematic expansive soils.

scholarly journals STABILIZATION OF EXPANSIVE SOIL WITH MIXING CA(OH)2 (EXPANSIVE SOIL CASE STUDY: JATILUHUR HAMLET, GLAGAH AGUNG VILLAGE, PURWOHARJO DISTRICT, BANYUWANGI REGENCY)

2019 ◽  
Vol 3 (1) ◽  
pp. 17
Author(s):  
Celia Nindy Carisa ◽  
Mokhammad Farid Ma'ruf ◽  
Paksitya Purnama Putra
Keyword(s):  
Expansive Soils ◽  
Clay Fraction ◽  
Expansive Soil ◽  
Special Treatment ◽  
Chemical Stabilization ◽  
Curing Time ◽  
Volume Changes ◽  
Lime Content ◽  
The Face

Expansive soils can cause problems in construction due to changing volume changes. The area that is suspected to have an expansive soil type is Glagah Agung village, Purwoharjo District, Banyuwangi. Every season change, the construction of the building is always damaged, especially on the structure of the building. In the rainy season, the land will expand and cause the building to rise, while at the dry season the land will shrink and there is a decline in buildings. In the face of these problems, it is necessary to do special treatment to improve the nature of the expansive soil. One is chemical stabilization, adding chemicals to improve soil properties and reduce their development potential. In this study, the stabilizers used are Ca (OH) 2 lime with a percentage of 4%, 6%, 8%, 10%, 12% with curing time for one day. The results of soil become less plastic with an increase of lime content. The decrease of plasticity index is supported by grain test which is the decrease of clay fraction grain on soil mixed with lime according to the USCS method and AASHTO method. There was a decrease in the percent of original primary soil development which was initially 11.9% decreased to 2.181% 4% lime content, and 0% at 6% to 12%. Tanah ekspansif dapat menimbulkan masalah dalam konstruksi akibat perubahan volume yang berubahubah. Daerah yang diduga memiliki jenis tanah ekspansif adalah Desa Glagah agung Kecamatan Purwoharjo, Kabupaten Banyuwangi. Setiap pergantian musim, konstruksi bangunan selalu mengalami kerusakan terutama pada struktur dari bangunan. Pada musim penghujan tanah akan mengembang dan mengakibatkan bangunan terangkat, sedangkan pada saat kemarau tanah akan menyusut dan terjadi penurunan bangunan. Dalam menghadapi permasalahan yang terjadi maka perlu dilakukan treatment khusus untuk memperbaiki sifat tanah ekspansif. Salah satunya adalah stabilisasi kimiawi, dengan menambahkan bahan kimia untuk memperbaiki sifat tanah dan mereduksi potensi pengembangannya. pada peneliatian ini, stabilitator yang digunakan adalah kapur Ca(OH)2 dengan prosentase 4%,6%,8%,10%,12% dengan waktu peram (curing) selama 24 jam. Didapatkan hasil tanah menjadi tidak plastis seiring dengan bertambahnya kadar kapur. Penurunan indeks plastisitas didukung dengan pengujian gradasi butiran yaitu berkurangnya butiran fraksi lempung pada tanah yang dicampur dengan kapur menurut metode USCS dan metode AASHTO. Terjadi penurunan persen pengembangan primer tanah asli yang mulanya sebesar 11,9% berkurang menjadi 2,181% kadar kapur 4%, dan 0% pada kadar 6% hingga 12%.

Performance Evaluation of Cement and Slag Stabilized Expansive Soils

2018 ◽  
Vol 2672 (52) ◽  
pp. 164-173 ◽  
Author(s):  
Masrur Mahedi ◽  
Bora Cetin ◽  
David J. White
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Atterberg Limits ◽  
Type I ◽  
High Plasticity ◽  
Swelling Potential ◽  
Laboratory Test Results ◽  
Addition Rate ◽  
Sulfate Salts ◽  
Type V

Swelling, shrinking, and subsequent low strength of expansive soil poses significant damage to structures if it is considered as foundation or fill material. Recently, the use of cement has become very prevalent in stabilizing these problematic soils owing to its effectiveness. However, the swelling potential of expansive soil is not always adequately resolved by cement. The presence of sulfate salts aggravates the situation impairing the effectiveness of cement, leading to the need to reassess its performance. In this study, the effectiveness of different stabilizers was investigated in stabilizing high-plasticity soil. Two types of soil with variable sulfate content were treated with slag, Type I/II, and Type V Portland cement, and their performances were evaluated based on Atterberg limits, pH, unconfined compression, and volumetric swell tests. A total of 312 samples were prepared for 18 different soil–stabilizer blends tested after 7, 28, and 90 days of curing period. Laboratory test results indicated that strength gain performance was attenuated and swelling potential increased due to the presence of sulfate salts. Adding stabilizers improved the strength of soils by a factor of 4–10 and decreased the swelling potential to < 1%. Atterberg limits decreased initially and then slightly increased with the increase of additive dosages. Additives increased the pH up to a maximum value of 11–12, which could be used as an indicator of target stabilizer addition rate. Finally, slag improved the performance of cement significantly and has proven to be a better option for treating high sulfate expansive soils.

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