scholarly journals Volume change behavior of unsaturated soils under non-isothermal conditions

2011 ◽  
Vol 56 (23) ◽  
pp. 2495-2504 ◽  
Author(s):  
GuoQing Cai ◽  
ChengGang Zhao ◽  
Yan Liu ◽  
Jian Li
Keyword(s):  
Volume Change ◽  
Unsaturated Soils ◽  
Isothermal Conditions ◽  
Change Behavior ◽  
Volume Change Behavior

scholarly journals Non-isothermal volume change behavior of saturated sand subjected to minimal vertical effective stress

2020 ◽  
Vol 205 ◽  
pp. 09008
Author(s):  
Yize Pan ◽  
Alessandro F. Rotta Loria
Keyword(s):  
Effective Stress ◽  
Volume Change ◽  
Current Knowledge ◽  
Coarse Grained ◽  
Saturated Sand ◽  
Isothermal Conditions ◽  
Heating And Cooling ◽  
Change Behavior ◽  
Volume Change Behavior ◽  
Vertical Effective Stress

To date, the majority of the available studies on the volume change behavior of soils under non- isothermal conditions have focused on fine-grained soils. Only a limited number of investigations have been made available about coarse-grained soils despite their abundance in practice, with contradictory features. To enrich the current knowledge about the volume change behavior of coarse-grained soils under non-isothermal conditions, this investigation presents the results of oedometric tests with temperature control performed on saturated sand. The influence of relative density on the volume change behavior of the tested material under non-isothermal conditions is investigated under a minimal level of applied vertical effective stress. The results show an expansive volume change upon heating and contractive volume change upon cooling for all relative densities. The magnitude of the contraction is more significant than that of the expansion, leading to a residual contractive volume change after one cycle of heating and cooling. The results of this study enrich the current literature about the volume change behavior of coarse-grained soils under non-isothermal conditions. Such competence may be considered for applications at the interface of geomechanics and energy wherein temperature variations occur and characterize the response of coarse-grained soils.

A hyperbolic model for volume change behavior of collapsible soils

1998 ◽  
Vol 35 (2) ◽  
pp. 264-272 ◽  
Author(s):  
G Habibagahi ◽  
M Mokhberi
Keyword(s):  
Bulk Modulus ◽  
Water Content ◽  
Volume Change ◽  
Unsaturated Soils ◽  
Computer Programs ◽  
Constitutive Relationship ◽  
Degree Of Saturation ◽  
Hyperbolic Model ◽  
Change Behavior ◽  
Volume Change Behavior

Finite element computer programs are frequently used to analyze and design embankments and similar earth structures. In most of the available computer programs, lack of a proper constitutive relationship to deal with volume change when an increase in the degree of saturation occurs, namely collapse phenomena, is a major handicap. In this paper, volume change results obtained from isotropic compression tests conducted on unsaturated compacted soil specimens are presented. Dependence of the bulk modulus of the soil on water content is investigated. Next, a hyperbolic formulation for volume change behavior of unsaturated soils taking into account variation of soil water content is presented. This hyperbolic model relates mean applied stress, volume change, and water content and represents a three-dimensional surface, the so-called "state surface". Suitability of the proposed model to predict collapse phenomena is verified by examining the model prediction against available experimental data.Key words: hyperbolic, unsaturated soil, collapse, volume change, suction pressure, bulk modulus.

Improvement of Strength and Volume-Change Properties of Expansive Clays with Geopolymer Treatment

2021 ◽  
pp. 036119812110018
Author(s):  
Rinu Samuel ◽  
Anand J. Puppala ◽  
Aritra Banerjee ◽  
Oscar Huang ◽  
Miladin Radovic ◽  
...  
Keyword(s):  
Volume Change ◽  
Carbon Dioxide Emissions ◽  
Expansive Soils ◽  
Linear Shrinkage ◽  
Plasticity Index ◽  
Specimen Preparation ◽  
Expansive Clays ◽  
Change Behavior ◽  
Volume Change Behavior ◽  
Lower Carbon

Expansive soils are conventionally treated with chemical stabilizers manufactured by energy-intensive processes that significantly contribute to carbon dioxide emissions globally. Geopolymers, which are synthesized from industrial byproducts rich in aluminosilicates, are a viable alternative to conventional treatments, as they are eco-friendly and sustainable. In this study, a metakaolin-based geopolymer was synthesized, and its effects on the strength and volume-change behavior of two native expansive soils from Texas, with a plasticity index over 20 were investigated. This paper elaborates on the geopolymerization process, synthesis of the metakaolin-based geopolymer, specimen preparation, and geopolymer treatment of soils. Comprehensive material testing revealed two clays with a plasticity index over 20. They were each treated with three dosages of the metakaolin-based geopolymer and cured in 100% relative humidity for three different curing periods. The efficiency of geopolymer treatment was determined by testing the control and geopolymer-treated soils for unconfined compressive strength (UCS), one-dimensional swell, and linear shrinkage. Field emission scanning electron microscope (FESEM) imaging was performed on the synthesized geopolymer, as well as on the control and geopolymer-treated soils, to detect microstructural changes caused by geopolymerization. A significant increase in UCS and reduction in swelling and shrinkage were observed for both geopolymer-treated soils, within a curing period of only 7 days. The FESEM imaging provided new insights on the structure of geopolymers and evidence of geopolymer formation in treated soils. In conclusion, the metakaolin-based geopolymer has strong potential as a lower-carbon-footprint alternative to conventional stabilizers for expansive soils.

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