Restriction of Volume Change and Improvement of Strength Properties of Problematic Soils Using Nano-natural Additives

2021 ◽  
Author(s):  
Aref M. Al-Swaidani ◽  
Ayman Meziab
Keyword(s):  
Volume Change ◽  
Strength Properties ◽  
Problematic Soils ◽  
Natural Additives

Engineering behavior of clay soils stabilized with class C and class F fly ashes

2018 ◽  
Vol 25 (2) ◽  
pp. 273-287 ◽  
Author(s):  
Evren Seyrek
Keyword(s):  
Fly Ash ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Strength Properties ◽  
Soil Samples ◽  
Fly Ashes ◽  
Swell Potential ◽  
Strength Tests ◽  
Problematic Soils ◽  
Swell Pressure

AbstractDamages and economical losses due to problematic soils have caused researchers to conduct many studies for the stabilization of these soils within years. Especially, the use of fly ashes in soil stabilization provides great benefits in contributing to the economy, as well as decreasing the environmental pollution. In the present study, the stabilization characteristics of soil-fly ash mixtures were evaluated in terms of Atterberg limits, compaction characteristics, swell potential and unconfined compressive strength with curing effect. To determine these effects, Catalagzi and Soma fly ashes obtained from Turkey were used in different proportions by weight for stabilization of clay soil samples. It was found that the plasticity index of the soils decreased considerably with the addition of fly ashes, while the strength improved and swell potential decreased. The decreasing trend in the swell percentage and swell pressure values decelerated especially after 25% fly ash additive content and negligible changes occurred. Similar behavior was observed in strength tests. Experimental results show that swelling and strength properties of the soils could be improved by using fly ash and Soma fly ash is far more effective than Catalagzi fly ash.

scholarly journals Effect of zeolite utilization on volume change and strength properties of expansive soil as landfill barrier

2017 ◽  
Vol 54 (9) ◽  
pp. 1320-1330 ◽  
Author(s):  
Şerife Öncü ◽  
Huriye Bilsel
Keyword(s):  
Hydraulic Conductivity ◽  
Volume Change ◽  
Expansive Soil ◽  
Confining Pressure ◽  
Good Alternative ◽  
Strength Properties ◽  
Landfill Liner ◽  
Swell Potential ◽  
Compressibility Characteristics ◽  
Natural Reserves

A sand–Na–bentonite mixture is widely used as engineering barrier material, which usually possesses hydraulic conductivity below the regulatory limit (10−7 cm/s). However, in some areas natural Na–bentonite is not readily available; instead, an abundantly prevailing local expansive soil can be an alternative. This study assesses the suitability of a local expansive soil mixed with zeolite, easily obtained from natural reserves in Turkey, proposed to be used as a landfill liner in a semi-arid climate. The choice of zeolite is due to its already well-understood high adsorption capacity for heavy metals as well as its pozzolanicity. The volume change, strength, and hydraulic conductivity characteristics were studied with respect to durability through ageing. When an expansive soil to zeolite ratio of 0.5 was used, the results indicated improved properties with curing. Swell potential was observed to decrease by 85% within a 90 day curing period, while a 30%–34% reduction was noted in shrinkage and compressibility characteristics. The hydraulic conductivity was observed to remain below the regulatory limit under all confining pressure ranges studied, provided the curing time was at least 90 days. Moreover, the mixture attained improved strength characteristics with time, and proved to be sustainable over the period studied. Therefore, it was concluded that expansive soil mixed with zeolite could be a good alternative to sand–Na-bentonite, mainly in developing areas of growing population and environmental degradation.

Effect of Volcanic Fines and Gradation on the Deformation and Strength Properties of Detrital Marine Sediments in Hawaii

2003 ◽  
Author(s):  
Horst G. Brandes ◽  
Tonya Johnson
Keyword(s):  
Marine Sediments ◽  
Volume Change ◽  
Frictional Resistance ◽  
Strength Properties ◽  
The Other ◽  
Shallow Waters ◽  
Kaneohe Bay ◽  
Frictional Strength ◽  
Calcareous Sands ◽  
Mixed Sediments

The compressibility and triaxial response of mixed sediments, consisting of volcanic and marine calcareous fractions, are investigated for a series of samples taken in the nearshore shallow waters of Kaneohe Bay in Hawaii. The results suggest that the presence of coarse detrital calcareous sands dominates the overall behavior if present in sufficiently large quantities, resulting in low compressibilities similar to that of silica sands and friction angles larger than that for most terrigenous sands at comparable densities. Larger than expected frictional resistance is attributed to the volume change tendencies of the non-uniform grains. On the other hand, when significant fines are present, whether of a volcanic nature or consisting of silty carbonate residue, compressibility tends to increase and frictional strength tends to decrease.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

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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