scholarly journals Wet Compaction and Lime Stabilization to Mitigate Volume Change Potential of Swelling Clayey Soils

2009 ◽  
Vol 49 (5) ◽  
pp. 813-821 ◽  
Author(s):  
Gilbertj Kasangaki ◽  
Ikuo Towhata
Keyword(s):  
Volume Change ◽  
Clayey Soils ◽  
Lime Stabilization

scholarly journals VOLUME CHANGE BEHAVIOR OF PHOSPHOGYPSUM TREATED CLAYEY SOILS CONTAMINATED WITH INORGANIC ACIDS – A MICRO LEVEL STUDY

2018 ◽  
Vol 26 (1) ◽  
pp. 8-18 ◽  
Author(s):  
Rama Vara Prasad CHAVALI ◽  
Hari Prasad Reddy P
Keyword(s):  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Volume Change ◽  
Contaminated Soils ◽  
Structural Changes ◽  
Sem Analysis ◽  
Clayey Soils ◽  
Volume Changes ◽  
Change Behavior ◽  
Volume Change Behavior

Soils exhibit undesirable volume changes when exposed to high concentrations of acids, which is manifested most frequently in the beds of foundations of industrial establishments associated with their production or use. However, control of this phenomenon has received less attention than it deserves. This paper aims to investigate the mineralogical and micro-structural changes occurred during the volume change behavior of phosphogypsum treated clayey soils contaminated with sulfuric acid and phosphoric acid solutions. Oedometer test results showed high swelling and low compressibility for acid contaminated soils than that of water. The change in microstructure towards flocculated fabric along with mineralogical transformations are responsible for the volume changes in soils. The mineralogical changes that affected the volume change behavior are discussed with FT-IR, XRD and SEM analysis. Phosphogypsum treatment was found to be effective in controlling volume changes in soils with phosphoric acid, whereas in the case of sulfuric acid found to be futile.

Improvement of Volume Change Characteristics of Saline Clayey Soils

2010 ◽  
Vol 11 (1) ◽  
pp. 76-85 ◽  
Author(s):  
R. Ziaie Moay ◽  
M. Haratian ◽  
E. Izadi
Keyword(s):  
Volume Change ◽  
Clayey Soils ◽  
Change Characteristics

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.

Incorporating Subgrade Lime Stabilization into Pavement Design

2000 ◽  
Vol 1721 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Bashar S. Qubain ◽  
Eric J. Seksinsky ◽  
Jianchao Li
Keyword(s):  
Resilient Modulus ◽  
Pavement Design ◽  
Clayey Soils ◽  
Highway Projects ◽  
Lime Stabilization ◽  
Somerset County ◽  
The Third ◽  
Prolonged Effect ◽  
Pavement Thickness ◽  
First Time

The benefits of subgrade lime stabilization are incorporated, for the first time, into the design of a major interstate highway pavement in Pennsylvania. The project comprises widening and complete reconstruction of 21 km of the Pennsylvania Turnpike in Somerset County. Field explorations indicated that the subgrade is fairly homogeneous and consists primarily of medium to stiff clayey soils. To safeguard against potential softening due to rain, lime modification has been traditionally utilized as a construction expedience for highway projects with clayey subgrade. Such an approach, however, does not take advantage of the added strength of the lime-stabilized subgrade in pavement design. Lime improves the strength of clay by three mechanisms: hydration, flocculation, and cementation. The first and second mechanisms occur almost immediately upon introducing the lime, and they have been investigated in the study; the third is a prolonged effect. Laboratory tests were performed to accurately capture the immediate benefits of lime stabilization for design. Both treated and natural clayey samples were subjected to resilient modulus and California bearing ratio testing. To prevent cementation, the lime-treated specimens were not allowed to cure. Nevertheless, they showed significant increases in strength, which, when incorporated into design, reduced the pavement thickness and resulted in substantial savings.

Volume Change Behavior of Two Compacted Clayey Soils under Hydraulic and Mechanical Loadings

2018 ◽  
Vol 144 (4) ◽  
pp. 04018013 ◽  
Author(s):  
Zhong-Sen Li ◽  
Feth-Ellah Mounir Derfouf ◽  
Assia Benchouk ◽  
Nabil Abou-Bekr ◽  
Said Taibi ◽  
...  
Keyword(s):  
Volume Change ◽  
Clayey Soils ◽  
Change Behavior ◽  
Volume Change Behavior

Artifacts caused by dehydration and epoxy embedding in TEM

1991 ◽  
Vol 49 ◽  
pp. 338-339
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Volume Change ◽  
Tissue Damage ◽  
Beam Specimen ◽  
Chemical Fixation ◽  
Resin Impregnation ◽  
Storage Vesicles ◽  
A Cell ◽  
Tissue Shrinkage

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.

Short-term volume and turgor regulation in yeast

2008 ◽  
Vol 45 ◽  
pp. 147-160 ◽  
Author(s):  
Jörg Schaber ◽  
Edda Klipp
Keyword(s):  
Dynamic Model ◽  
Volume Change ◽  
Volume Regulation ◽  
Time Course ◽  
Osmotic Shock ◽  
Intracellular Concentration ◽  
Short Term ◽  
Hydrodynamic Property ◽  
Turgor Regulation ◽  
Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

FREE VOLUME CHANGE OF METALLIC GLASSES STUDIED BY THERMAL EXPANSION MEASUREMENTS

1980 ◽  
Vol 41 (C8) ◽  
pp. C8-875-C8-877
Author(s):  
E. Girt ◽  
P. Tomić ◽  
A. Kuršumović ◽  
T. Mihać-Kosanović
Keyword(s):  
Thermal Expansion ◽  
Free Volume ◽  
Volume Change ◽  
Metallic Glasses
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