Kalpana Katti - Thesis Committee

Permanent URI for this collectionhdl:10365/32109

Browse

Browsing Kalpana Katti - Thesis Committee by Subject "Swelling soils"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Clay Fluid Interactions in Montmorillonite Swelling Clays: A Molecular Dynamics and Experimental Study
    (North Dakota State University, 2012) Patwary, Md Zillur R.
    Swelling clays cause tremendous amounts of damage to infrastructure. For the effective prevention of detrimental effects of these clays, and to optimize the beneficial properties for industrial applications it is necessary to clearly understand the fundamental mechanisms of swelling of clays. In this study, we studied the effect of fluid polarity on swelling and flow properties of swelling clays using molecular modeling and experimental technique for bridging the molecular level phenomenon of these clays with microstructure change, particle breakdown and macro scale swelling and flow properties. A wide range of fluids (Dielectric Constant 110 to 2.4) were used, those are also commonly present in landfill leachates. We were able to tie the properties of swelling clays at different length scales. Then, we simulated the solvation of clay sheets, studied the effect of discrete charge distribution, contribution of edge charges on swelling clays and discussed some fundamental assumptions associated with double layer theories.
  • No Thumbnail Available
    Item
    Initial Swelling Mechanism of Expansive Clays: A Molecular Dynamics Study
    (North Dakota State University, 2012) Srinivasamurthy, Lakshmikanth
    Expansive soils are widely found in many parts of the world. Highly active smectite clay mineral Montmorillonite is the major constituent in these clays and can expand or contract up to 15 times of their original volume. Constrained swelling exert large amount of stress causing damage to structures, pavements etc. These clays are also used as barrier materials, Nano-materials in polymer clay Nano composites and drug delivery systems. Several factors influence the swelling potential such as water content, density, voids, electrolyte content and cation exchange capacity. However, molecular scale mechanisms that control swelling behavior in these clays need to be understood. Objectives of this research are to provide an insight into mechanisms that result in swelling of these clays. Molecular modeling is used to build and study solvation of Na-Montmorillonite system. Trajectories of water molecules are captured and the evolutions of interaction energies with swelling are calculated.