Long-term durability analysis and lifetime prediction of PVC waterproofing membranes

Water inflow is an important issues in tunnels because it causes damage to structures and plants. Waterproofing systems are a key aspect for an effective design. Risk analysis can be useful to design the waterproofing, considering long-term efficiency and costs. Moreover, durability is important due to the lifetime requirements of modern tunnels. Nevertheless, there is a lack of knowledge on this aspect for waterproofing membranes. PVC, which is one of the most used materials for this application, is degrades due to loss of plasticizers and polymer alteration. Accelerated ageing tests have been developed to study its long-term durability, but none of those is simulating the real conditions of the membrane in a tunnel. Therefore, an accelerated aging test simulating the tunnel conditions, i.e. water flow on the PVC between concrete layers, has been developed. The mechanical parameters of aged specimens are studied to develop a long-term extrapolation of the results to the non-accelerated jobsite conditions