STP1095: Influence of Some Environmental Activities on Physical and Mechanical Behavior of Clays

    Pamukcu, S
    Assistant professor, graduate research assistant, and professor, Lehigh University, Bethlehem, PA

    Tuncan, M
    Assistant professor, graduate research assistant, and professor, Lehigh University, Bethlehem, PA

    Fang, H-Y
    Assistant professor, graduate research assistant, and professor, Lehigh University, Bethlehem, PA

    Pages: 17    Published: Jan 1990


    Abstract

    Chemical contamination of clays during depositional and postdepositional periods influences their physical and mechanical properties. Laboratory-prepared specimens mixed with various percentages of contaminating agents were tested to assess some of these influences. Municipal sludge, fly ash, and fuel oil were selected to represent the contaminating agents. The laboratory specimens were prepared using pure clay minerals or mixtures of them. A part of the specimens was prepared through consolidating the initial slurry, and part was prepared by sedimentation. Variation of shear modulus, permeability, and compressibility with increasing percentages of sludge and fly ash were analyzed for a number of consolidated kaolinite specimens. Some of the behavior was explained through influences of contamination on the formation of clay structure. Scanning electron micrographs were utilized to find evidence in support of the observed behavior. Similar studies were conducted on laboratory-prepared, consolidated marine clay samples. The shear modulus of both fuel oil and sludge mixed samples were found to decrease. The decrease was most significant in the fuel oil sample. This was attributed to the formation of an open, loose microstructure and the increased water-holding capacity of the specimen. The rate of settlement of sedimented clays were found to be influenced by the presence of contaminating agents.

    Keywords:

    physico-chemistry, clays, pollution, microstructure, mechanical properties


    Paper ID: STP23550S

    Committee/Subcommittee: D18.06

    DOI: 10.1520/STP23550S


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