Durability of PVC-P geomembranes used in hydraulic structures: feedback on experience

PVC-P geomembranes are widely used to ensure the watertightness of hydraulic structures. The authors have observed widely varying behaviour in these geomembranes over time, depending on the conditions in which they are used and on the quality of the PVC-P employed; although durability was in most cases satisfactory and in line with forecasts, some cases of very rapid ageing were also observed. This then raises the question for users of defining criteria for choosing a PVC-P geomembrane. On the basis of a bibliographical study and of analyses of samples taken from structures, examples of satisfactory behaviour as well as of premature ageing are presented. They involve geomembranes used with and without protective cover.