scholarly journals Effect of Three Bioenzymes on Compaction, Consistency Limits, and Strength Characteristics of a Sedimentary Residual Soil

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tanveer Ahmed Khan ◽  
Mohd Raihan Taha
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Soil Improvement ◽  
Soil Samples ◽  
Atterberg Limits ◽  
Residual Soil ◽  
X Ray Diffraction ◽  
Compaction Characteristics ◽  
X Ray ◽  
Curing Period

Bioenzymes are organic degradable materials, currently introduced as soil improvement additives. In this experimental study, three types of bioenzymes from three different countries were used to improve Universiti Kebangsaan Malaysia (UKM) soil. UKM soil has properties quite similar to soils recommended as suitable by bioenzyme suppliers. The effect of the three bioenzymes on Atterberg limits, compaction characteristics, and unconfined compressive strength was studied. Controlled untreated and treated samples for two dosages at curing times up to three months were prepared and tested after completion of the curing period. Some results showed little improvement in compaction characteristics, and unconfined compressive strength, but no notable improvement was noticed in Atterberg limits. X-ray diffraction (XRD), X-ray fluorescence (XRF), and field emission scanning electron microscopy (FESEM) tests were conducted for untreated and treated soil samples after two months of curing. XRD and XRF did not show any change in mineralogy and chemical composition between controlled untreated samples and samples treated with the three bioenzymes. However, the FESEM images revealed a denser packing of particles for soil samples treated with two of the bioenzymes.

scholarly journals Strength and Volume Change Characteristics of Clayey Soils: Performance Evaluation of Enzymes

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 52
Author(s):  
Tanveer Ahmed Khan ◽  
Mohd Raihan Taha ◽  
Mudasser Muneer Khan ◽  
Syyed Adnan Raheel Shah ◽  
Muhammad Asif Aslam ◽  
...  
Keyword(s):  
Volume Change ◽  
Unconfined Compressive Strength ◽  
Optimum Moisture Content ◽  
Soil Samples ◽  
Residual Soil ◽  
Clayey Soils ◽  
X Ray Diffraction ◽  
Treated Soil ◽  
X Ray ◽  
Change Characteristics

This study was conducted to evaluate the strength and volume change characteristics of a sedimentary residual soil mixed with bentonite (S1) when treated with three different enzymes. In addition, three reference clays including bentonite, illite, and kaolinite were also treated with enzymes to study the effect on their strength characteristics. Soil samples prepared at the optimum moisture content (OMC) were sealed and cured for four months. After curing, reference clays were tested for unconfined compressive strength (UCS). For swell tests, the S1 soil samples were placed on porous stones, which were immersed in water to allow capillary soaking of the samples. S1 samples were allowed to dry at ambient temperature for shrinkage test until the rate of reduction in volume became negligible. On completion of swell tests, the samples were tested for UCS to determine the decrease in strength due to saturation. No increase in strength and decrease in volume change were observed for any of the enzymes and dosages. Field Emission Scanning Electron Microscope (FESEM) showed some dense packing of particles for treated samples, whereas X-ray diffraction (XRD) did not reveal any change; in fact, the pattern for untreated and treated soil samples were indistinguishable.

Experimental Researches on Microstructure of Nanometer Silicon and Cement-Stabilized Soils

2011 ◽  
Vol 94-96 ◽  
pp. 358-364 ◽  
Author(s):  
Li Feng Wang
Keyword(s):  
Compressive Strength ◽  
Calcium Silicate ◽  
Unconfined Compressive Strength ◽  
Silicon Powder ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Silicate Hydrates ◽  
Stabilized Soil ◽  
Experimental Researches

Unconfined compressive strength of various mixing proportions and ages of nanometer silicon and cement-stabilized soils（NCSS） are tested ,and the rules of compressive strength are got. Hydration products and microstructures of NCSS are discussed by means of XRD and SEM technology, and microstructural mechanisms of NCSS are analyzed. Results show that nanometer silicon powder added to cement-stabilized soil(CSS) can sharply improve the compressive strength of CSS. More Calcium silicate hydrates(C-S-H) and other hydration products can be produced in the process of secondary reaction of cement and water added nanometer silicon powder. X ray diffraction tests indicate the kinds and quantities of C-S-H increase with nanometer silicon contents. Strengths of NCSS are bettered by increasing jointed strength changed from edge-edge, edge-face connectios to cementation connections affected by increasing hydration products. Large pores of NCSS can be greatly decreased by adding nanometer silicon powder, and hydration products filling in the pores make NCSS more dense materials.

scholarly journals Black Cotton Soil Stabilization by Using Fly Ash - Kota Stone Slurry Mix

2021 ◽  
Vol 9 (11) ◽  
pp. 1699-1703
Author(s):  
Phoolwanti Nanda
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Atterberg Limits ◽  
Black Cotton Soil ◽  
Strength Development ◽  
Dry Density ◽  
X Ray ◽  
Soil Stabilizer

Abstract: The usage of waste material for stabilizing black cotton soil has been a sustainable interest. Kota stone slurry is a waste from kota stone and fly ash is a waste from industries containing high amount of sodium and magnesium, was used as a soil stabilizer for blac cotton soil improvement in this study. This research investigated the effects of sizes and percentages of kota stone slurry mix and fly ash on the physical and strength properties, which included particle size distribution, Atterberg limits, compaction, and unconfined compressive strength (UCS) of blac cotton soil. Micro structural characterization, including the scanning electron microscopic, energy dispersive X-ray spectroscopy, and X-ray diffraction was conducted on both untreated and treated black cotton soil samples to examine the mechanism of strength development. The addition of kota stone slurry and fly ash reduced the water holding capacity, which then caused the reduction in soil plasticity (from 18 to 11%) and optimum water content (from 20 to 16%) along with the increase in peak dry density (from 1.66 to 1.74 Mg/m3). The strength of black cotton soil may increased from 50 to almost 220 kPa. The optimum kota stone slurry and fly ash contents, providing the highest UCS, were at 20 and 30% for 0.063 mm kota stone slurry and fly ash and 0.15 mm kota stone slurry and fly ash, respectively. The UCS improvement of treated marine clay is attributed to the formation of cementation compounds, mainly aluminum magnesium silicate hydrate (A–M–S–H). The outcome of this research will allow the use of RBT as a low-carbon soil stabilizer across civil engineering applications. Keywords: Stablization, Fly ash, kota stone slurry, Atterberg limits, Compaction, and unconfined compressive strength

scholarly journals Bio-Mediated Soil Improvement Using Plant Derived Enzyme in Addition to Magnesium Ion

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 516
Author(s):  
Md Al Imran ◽  
Kazunori Nakashima ◽  
Satoru Kawasaki
Keyword(s):  
Unconfined Compressive Strength ◽  
Xrd Analysis ◽  
Soil Improvement ◽  
Magnesium Ion ◽  
Carbonate Precipitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Sand Particles ◽  
Lower Molar

Recently, soil improvement using EICP (Enzyme-Induced Carbonate Precipitation) methods in the geotechnical and geo-environmental field has become a prominent interest worldwide. The objective of this study was to develop an improved extraction technique of crude urease from watermelon seeds in both dry and germinated conditions. Subsequently, this study also analyzed the improvement methodology of crystal polymorphs and soil bonding incorporation of various Mg2+/Ca2+ ratios. The optimization of enzyme-mediated carbonate precipitation was also investigated by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis. Results confirmed that the precipitated crystals are mainly calcite, vaterite and aragonite primarily (depending on the Mg2+/Ca2+ ratios). Therefore, to improve the bonding capacity in between the sand particles a novel improvement methodology was investigated by adding various Mg2+/Ca2+ ratios. The mechanical properties of the treated soil (Mikawa Sand, D50 = 0.870 mm) specimens were tested by unconfined compressive strength (UCS) and this confirmed the effectiveness of adding various Mg2+/Ca2+ ratios. The results of the UCS tests showed that, the lower molar ratios of Mg2+/Ca2+ can significantly improve the UCS of the specimen (up to 50%) which could be considered a significant outcome for different bio-geotechnical applications.

scholarly journals Experimental Study of the Effects of Some Selected Geotechnical Indices on the Unconfined Compressive Strength of Lateritic Soil

2019 ◽  
Vol 2 (Issue 1) ◽  
Author(s):  
G.O Adunoye ◽  
O.C Onah ◽  
F.O Ajibade
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Soil Samples ◽  
Atterberg Limits ◽  
Effective Size ◽  
Natural Moisture Content ◽  
Coefficient Of Uniformity

This study undertook an experimental study of the comparative effects of Atterberg limits, particles size and compaction parameters on the unconfined compressive strength of selected soils. This was with a view to ascertaining which of the combinations of the soil properties will produce a good prediction of the unconfined compressive strength. To achieve this aim, soil samples were obtained from selected locations within Ife Central Local Government Area, Osun State, Nigeria. The following tests were conducted on the soil samples, following standard procedures: natural moisture content determination, specific gravity, Atterberg limits, compaction and unconfined compressive strength. Using Regression tool, the results obtained from the laboratory tests were used to develop the relationships between each of the index properties and unconfined compressive strength. Results showed that the natural moisture content of soil samples ranges between 18.48 % and 25.03 %; specific gravity ranges between 2.35 and 2.69; liquid limit ranges between 39.95 % and 83.98 %; plastic limit ranges between 29.32 % and 51.18 %; and plasticity index is between 8.74 % and 33.56 %. The maximum dry density ranges between 15.30kN/m3 and 19.30kN/m3 with their optimum moisture contents ranging between 13.80 % and 35.50 % while unconfined compressive strength is between 36.00 kN/m2 and 97.14 kN/m2. The results of regression analysis showed that effective size and coefficient of uniformity have the greatest effect (R2 = 0.82) on unconfined compressive strength of the tested soil samples. Therefore, the study concluded that effective size and coefficient of uniformity could be used to estimate the unconfined compressive strength of the soils.

Effect of P2O5 on the Properties of Alite-Calcium Strontium Sulphoaluminate Cement

2011 ◽  
Vol 306-307 ◽  
pp. 961-965
Author(s):  
Chao Nan Yin ◽  
Ling Chao Lu ◽  
Shou De Wang
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Heat Evolution ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulphoaluminate Cement ◽  
Suitable Amount ◽  
Acceleration Period ◽  
Scanning Electron

The influence of P2O5on the properties of alite-calcium strontium sulphoaluminate cement was researched by means of X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and petrographic analysis. The results show that the optimal content of P2O5is 0.3% and the compressive strength of the cement at 1, 3, 28d are 27.0, 59.1, 110.9MPa when the calcining temperature is 1350°C. P2O5mainly exists in the belite and a suitable amount of P2O5can promote the formation of C1.5Sr2.5A3and alite. When the content of P2O5is higher than 0.3%, the formation of C1.5Sr2.5A3and alite can be hindered. P2O5can enhance the hydration heat evolution rate in the acceleration period and the hydrate heat of cement containing P2O5increases slightly.

Macrostructural and Microstructural Properties of Residual Soils as Engineered Landfill Liner Materials

2021 ◽  
Author(s):  
Lee Li Yong ◽  
Vivi Anggraini ◽  
Mavinakere Eshwaraiah Raghunandan ◽  
Mohd. Raihan Taha
Keyword(s):  
Tap Water ◽  
Chemical Precipitation ◽  
Soil Samples ◽  
Residual Soil ◽  
Diffuse Double Layer ◽  
Microstructural Properties ◽  
Residual Soils ◽  
Soil Leachate ◽  
Landfill Liner ◽  
X Ray

ABSTRACT This study assessed the performance of residual soils with regard to their macrostructural and microstructural properties and compatibility with leachate in pursuit of exploring alternative cost-effective and efficient landfill liner materials. A series of laboratory investigations was conducted on three residual soil samples by using tap water and leachate as permeation fluid to achieve the objectives of the study. The zeta potential measurements revealed that the presence of multivalent cations in the leachate decreased the diffuse double layer (DDL) thickness around the soil particles. The reduced DDL thickness caused a decrease in Atterberg limits of soil-leachate samples and changes in the classification of fine fractions. Additionally, the effects of pore clogging attributed to chemical precipitation and bioclogging were responsible for the reduction in measured hydraulic conductivities of soil-leachate samples. These effects can be clearly observed from the field-emission scanning electron microscopy images of soil-leachate samples with the appearance of less visible voids that led to a more compact and dense structure. The formation of new non-clay minerals and associated changes in the Al and Si ratio as reflected in the x-ray diffraction diffractograms and energy-dispersive x-ray analyses, respectively, were attributed to the effects of chemical precipitation. This study concluded that S1 and S2 residual soil samples are potential landfill liner materials because they possess adequate grading characteristics, adequate unconfined compressive strength, low hydraulic conductivity, and good compatibility with leachate. In contrast, the S3 sample requires further treatment to enhance its properties in order to comply with the requirements of landfill liner materials.

Stabilization of Black Cotton Soil using Lime and Phosphogypsum

2021 ◽  
Vol 9 (4) ◽  
pp. 503-507
Keyword(s):  
Unconfined Compressive Strength ◽  
Expansive Soils ◽  
Soil Samples ◽  
Black Cotton Soil ◽  
Stabilization Method ◽  
Curing Period ◽  
Problematic Soils ◽  
Construction Purpose ◽  
Black Cotton Soils ◽  
Properties Of Soil

Expansive soils are problematic soils for Civil Engineers. Black cotton (BC) soils possess low strength and high compressibility, due to these properties black cotton soils are considered to be challenging one for analysis. To achieve desired properties of soil for construction purpose these black cotton soil must be enhanced to meet its requirement. To modify the properties of black cotton soils, many treatment methods are there. In this paper an attempt has been made to improve the properties of black cotton soil by using industrial waste through stabilization method. By stabilizing the soil properties are enhanced and make it suitable for subgrade construction. In this work, the combined effect of Lime and Phosphogypsum (PG) on compaction characteristics, Atterberg’s Limit, Unconfined Compressive Strength (UCS) for original soil, California Bearing Ratio (CBR) and direct shear Test of a black cotton soil with percentage varying of Lime and Phosphogypsum was carried out. The soil samples were tested for tri-axial compression test and CBR tests were carried out after 4 days curing period. From the results, it has been inferred that the black cotton soil treated with Lime and Phosphogypsum in the percentages of (4:4) has better strength characteristics. Hence, it may be concluded that Lime and Phosphogypsum can be used for stabilization of black cotton soils for pavement subgrade

Effect of Fly Ash and Slag on the Resistance to H2S Attack of Oil Well Cement

2009 ◽  
Vol 79-82 ◽  
pp. 71-74
Author(s):  
Qi Wang ◽  
Lin Qiao ◽  
Peng Song
Keyword(s):  
Fly Ash ◽  
Compression Strength ◽  
Blended Cement ◽  
Oil Well ◽  
X Ray Diffraction ◽  
X Ray ◽  
Curing Period ◽  
Oil Well Cement ◽  
Xrd Patterns ◽  
Well Cement

In this paper, the resistance to H2S attack of pastes made from slag-fly ash blended cement used in oil well (SFAOW) was studied, in which fly ash (FA) was used at replacement dosages of 30% to 60% by weight of slag. Samples of SCOW and SFAOW pastes were demoulded and cured by immersion in fresh water with 2 Mp H2S insulfflation under 130oC for 15 days. After this curing period, compression strength and permeability of the samples were investigated. The reaction mechanisms of H2S with the paste were carried out through a microstructure study, which included the use of x-ray diffraction (XRD) patterns and scanning electron microscope (SEM). Based on the obtained data in this study, incorporation of FA into SCOW results in the comparable effects in the resistance to H2S attack. When the replacement dosage of slag is about 40%, the paste exhibits the best performance on resistance to H2S attack with compression strength 36.58Mp.

scholarly journals Effect of Locally Available Wheat Straw Ash in Developing High Strength Concrete

2021 ◽  
pp. 19-28
Author(s):  
Muhammad Armaghan Siffat ◽  
Muhammad Ishfaq ◽  
Afaq Ahmad ◽  
Khalil Ur Rehman ◽  
Fawad Ahmad
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Wheat Straw ◽  
High Strength Concrete ◽  
High Strength ◽  
Optimum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strength Concrete ◽  
Straw Ash

This study is supervised to assess the characteristics of the locally available wheat straw ash (WSA) to consume as a substitute to the cement and support in enhancing the mechanical properties of concrete. Initially, after incineration at optimum temperature of 800°C for 0.5, the ash of wheat straw was made up to the desirable level of fineness by passing through it to the several grinding cycles. Subsequently, the X-ray fluorescence (XRF) along with X-ray diffraction (XRD) testing conducted on ash of wheat straw for the evaluation its pozzolanic potential. Finally, the specimens of concrete were made by consuming 10% and 20% percentages of wheat straw ash as a replacement in concrete to conclude its impact on the compressive strength of high strength concrete. The cylinders of steel of dimensions 10cm diameter x 20cm depth were acquired to evaluate the compressive strength of high strength concrete. The relative outcomes of cylinders made of wheat straw ash substitution presented the slight increase in strength values of the concrete. Ultimately, the C-100 blends and WSA aided cement blends were inspected for the rheology of WSA through FTIR spectroscopy along with Thermogravimetric technique. The conclusions authenticate the WSA potential to replace cement in the manufacturing of the high strength concrete.

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