Asperity height or asperity concentration: what matters more for interface shear resistance on textured polyethylene (PE) geomembranes?

Blond and Elie (2006) highlighted the parameters that influence interface shear behaviour in polyethylene (PE) geomembranes. Several parameters were evaluated in the study and the outcome in-dicated that asperity height was a key shear strength determining parameter. This paper presents a new way of texturing (micro texturing) that gives the geomembrane surface closer spaced asperity and a higher asperity concentration. These characteristics increases surface roughness and create a wider interface areal contact, enabling the micro textured surface to achieve higher interface shear resistance at moderate asper-ity heights. Initial results from interface shear testing on PE geomembranes with the micro textured sur-face extend the Blond and Elie’s findings on the contribution of asperity height to interface shear strength, by indicating that in addition to asperity height, an equally important parameter to consider for increased interface shear resistance may be asperity concentration. This paper presents the micro textured geomem-brane surface, and a comparison of the interface shear test results for micro textured geomembranes with an asperity height of 17 mils and other textured geomembranes with various asperity heights in contact with hydrated geotextile and geocomposite surfaces.