rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Sulfate induced heave
    sub title: addressing ettringite behavior in lime treated soils and in cementitious materials
  name:
    name part: Kochyil Sasidharan Nair, Syam Kumar.
    role:
      role term: creator
  name:
    name part: Little, Dallas N.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2012
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: Civil engineers are at times required to stabilize sulfate bearing clay soils with calcium based stabilizers. Deleterious heaving in these stabilized soils may result over time. This dissertation addresses critical questions regarding the consequences of treating sulfate laden soils with calcium-based stabilizers. The use of a differential scanning calorimeter was introduced in this research as a tool to quantify the amount of ettringite formed in stabilized soils. The first part of this dissertation provides a case history analysis of the expansion history compared to the ettringite growth history of three controlled low strength mixtures containing fly ash with relatively high sulfate contents. Ettringite growth and measurable volume changes were monitored simultaneously for mixtures subjected to different environmental conditions. The observations verified the role of water in causing expansion when ettringite mineral is present. Sorption of water by the ettringite molecule was found to be a part of the reason for expansion. The second part of this dissertation evaluates the existence of threshold sulfate levels in soils as well as the role of soil mineralogy in defining the sensitivity of soils to sulfate-induced damage. A differential scanning calorimeter and thermodynamics based phase diagram approach are used to evaluate the role of soil minerals. The observations substantiated the difference in sensitivity of soils to ettringite formation, and also verified the existence of a threshold level of soluble sulfates in soils that can trigger substantial ettringite growth. The third part of this dissertation identifies alternative, probable mechanisms of swelling when sulfate laden soils are stabilized with lime. The swelling distress observed in stabilized soils is found to be due to one or a combination of three separate mechanisms: (1) volumetric expansion during ettringite formation, (2) water movement triggered by a high osmotic suction caused by sulfate salt…
  note: by Syam Kumar Kochyil Sasidharan Nair.
  note: "Major Subject: Civil Engineering"
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2010 http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8905
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major civil engineering
  subject:
    topic: Threshold sulfate level
  subject:
    topic: Volume change
  subject:
    topic: Soil suction
  subject:
    topic: Controlled low strength materials (CLSM)
  subject:
    topic: Crystal growth
  subject:
    topic: Sulfate heave
  subject:
    topic: Nucleation
  subject:
    topic: Soil stabilization
  subject:
    topic: Ettringite
  subject:
    topic: Cementitious materials
  subject:
    topic: Portland cement concrete
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8905
  record info:
    record content source: TXA
    record creation date: 120306
    record change date: 20151202151659.0
    record identifier: in00002746692