Long-term durability assessment of PVC-P waterproofing geomembranes through laboratory tests.

• Plasticizer loss is the main phenomenon affecting the durability of PVC membranes. • A device for accelerated ageing tests on PVC membranes has been developed. • Mechanical tests are performed to study the time-dependent properties of membranes. • Plasticizer loss with time has been modelled from plasticizer absorption tests data. • The end-of-life time of the two commercial PVC membranes is evaluated. Waterproofing heavily influences the operation and maintenance costs of underground structures. Currently, the most commonly used technology for tunnel waterproofing is plasticized polyvinyl chloride (PVC-P) geomembranes. However, not much is known about the long-term durability of these geomembranes, especially in relation to the long expected lifespan of new tunnels (i.e. 100–150 years). Therefore, in this paper, the durability of two commercially available PVC-P geomembranes is studied with the help of a specifically designed accelerated ageing device in addition to mechanical and absorption tests. The degradation resulting from plasticizer loss is extrapolated to the long term, and a threshold value for the end-of-life of the PVC-P geomembrane is estimated from the mechanical tests. [ABSTRACT FROM AUTHOR]