ABSTRACT
The quality of HDPE field seams depends on factors related to the geomembrane itself, welding parameters identified from the type of equipment and welding technique used and the field constraints such as climatic conditions and project design. Significant progress in the improvement of field techniques is needed in order to achieve satisfactory quality assurance. Using a microscopic technique, cross sections of seams can be analysed to observe molecular abnormalities, identify micro stress cracks within the bonded sheets, detect unbonded areas and observe slow crack growth phenomena. An impact test of a HDPE field seam can be performed with a drop-weight apparatus, in order to produce proper immediate failure. The mean failure energy can be reported as the seam fail or pass upon application of an adequate drop-weight mean energy. The shear and peel methods are modified versions of ASTM standards developed to measure the tensile and peel properties of very thin plastic-sheeting seams.
