Effect of suction change on water content and total volume of an expansive clay

2007 ◽  
Vol 8 (5) ◽  
pp. 699-706 ◽  
Author(s):  
Liang-tong Zhan ◽  
Ping Chen ◽  
C. W. W. Ng
Keyword(s):  
2017 ◽  
Vol 23 (2) ◽  
pp. 124
Author(s):  
Wilis Diana ◽  
Edi Hartono ◽  
Anita Widianti

Expansive soils experience volumetric changes due to water content changes. These volumetric changes cause swell and shrink movement in soils, which in turn will inflict severe damage to structures built above them. A Proper understanding of how the expansive soil behaves during the wetting/drying process is essential for assessing the mitigation action of expansive soil hazard and design suitable foundation. The structures that build above expansive soil bed are susceptible to heave and to withstand swell pressure, thus the swell pressure must be considered in the design. This study focuses on swelling properties of two expansive clay from Ngawi, East Java and Wates, Yogyakarta. Laboratory test on disturbed samples is used to identified and to measured swelling properties. A series of swelling test was performed under constant soil dry density. The influence of initial water content and surcharge pressure on swelling properties (i.e swell percent and swell pressure) of compacted samples were investigated. The swelling properties test used ASTM standard 4546-03 method B. It was found that the lower initial water content the higher the swell percent, but the swell pressure seems not to be affected by initial water content. At the same initial water content, swell percent decrease with the increase of surcharge pressure, but swell pressure remains unchanged.


2020 ◽  
Vol 195 ◽  
pp. 03009
Author(s):  
Damian V A Alexander ◽  
Kyung Ho Park ◽  
Derek Anthony Gay

Volume change behaviour of expansive clays has been one of the leading causes of damage to civil infrastructures worldwide. Contributing factors that lead to failures relate to changes in water content within the soil. Variations of water content can vary significantly based on an area’s climate regime. Trinidad has two seasons, the dry season (January to June) and the wet season (July to December). This variation leads to volume changes of expansive clay, where they exist mainly within the central and south regions of Trinidad. These areas are densely populated by residential and commercial buildings, which can be susceptible to damages from unsaturated expansive clays. The Soil Water Characteristic Curve (SWCC) for expansive clays is critical to estimate their unsaturated properties for the analysis of water flow movement. This study investigates the SWCCs for two expansive clay soil types in Trinidad. A WP4-T (Water Potential Measurement) is used to measure soil suction. The shrinkage curve (SC) test is conducted to consider the volume change of soil. The Fredlund and Xing (1994) SWCC equation and Fredlund and Zhang (2013) SC equation are used to fit the measured data. The SWCCs in terms of gravimetric and volumetric water contents and degree of saturation are compared. It is found that the normalised degree of saturation SWCC can provide a better display of the SWCC and estimation of the air-entry value.


Author(s):  
Songquan Sun ◽  
Richard D. Leapman

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.


Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.


1982 ◽  
Vol 43 (C9) ◽  
pp. C9-455-C9-458 ◽  
Author(s):  
M. Takata ◽  
M. Tomozawa ◽  
J. Acocella ◽  
J. Molinelli ◽  
C. Y. Erwin ◽  
...  

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
SULASMI ANGGO

The Analysis of physical chemical from dara shells (Anadara granosa) origin from Kayutanyo, kab. Banggai, has been conducted.Dara shell meat is sleaned and dried and after that powered with blender. Determine % rendement, water bonding capacity and index water solubility with Anderson method, coarse fat content with gravimetric method and carbohydrate method with “bye difference” decrease method.The result of analysis showed rendement value is 24,35%, water bonding capacity is 1,6248 gram/ml, index water solubility is 0,202 gram/ml, water content is 79,0045%, total dust content is 1,072%, coarse protein content is 2,25%, coarse fat content is 8,47%, carbohydrate content is 9,2035%. Keyword : Dara shells, (Anadara granosa), analysis physical chemical


Author(s):  
M.C.H.Mouat Pieter Nes

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.


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