STP1076: Microscopic Evaluation of High-Density Polyethylene Geomembrane Field-Welding Techniques

    Rollin, AL
    Ecole Polytechnique of Montreal, Montreal,

    Vidovic, A
    Ecole Polytechnique of Montreal, Montreal,

    Denis, R
    Solmers Internationale, Montreal,

    Marcotte, M
    Solmers Internationale, Montreal,

    Pages: 14    Published: Jan 1990


    Abstract

    An investigation on seam quality of high-density polyethylene geomembrane has been conducted to demonstrate the importance of microscopic analyses for seam quality evaluation. Shear and peel tests were conducted to assess the quality of polyethylene geomembrane seams produced by known welding techniques, while sample cross sections of welds were analyzed using microscopic techniques. The shear and peel tests are usually performed to obtain quantitative measurements of seam strength. These test results are used as acceptance criteria to evaluate the bond strength. However, they do not adequately characterize molecular structure changes nor identify microstress cracks within the bonded sheets. Microscopic phenomena that may not be observed by these tests include contact areas where the depth of the melted polymer is very thin, displacement of a mass of polymer towards the edge of the seam, and formation of longitudinal channels across the seam. Microscopic photographs of seam cross sections are presented and discussed to evaluate seam quality.

    Keywords:

    geomembranes, seam, shear test, peel test, microscopic analysis


    Paper ID: STP23495S

    Committee/Subcommittee: D35.10

    DOI: 10.1520/STP23495S


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