SilverSeal Self Sealing Membrane

Sealing systems with synthetic waterproofing membranes in tunnel construction require frequent repair work in order to be able to maintain the necessary impermeability. The causes can be found not only in the design, but also in the execution. The work opera-tions, such as the reinforcement installation or the concreting of the inner shell, follow-ing the installation of the sealing system can lead to damage to the sealing system. As a result, damp and wet spots occur that can only be redressed through costly injection campaigns.

Therefore, an innovative sealing system
SilverSeal

has been developed by BPA-GmbH that, if damaged, “self-healingly” seals the synthetic waterproofing membrane (SWM) and in the event of damage prevents the running behind of mountain water between the SWM and the cast in-situ concrete inner shell.
The solution consists of an SWM on which a thin, swelling polymer-consisting fleece is laminated. On concreting the inner shell, the fleece forms a bond with the wet concrete and, due to the bond, in the event of damage to the SWM, prevents the longitudinal and / or lateral traversing of the mountain water. Due to the swelling properties of the fleece, an additional waterproof barrier is formed on the ingress of water. Damaged ar-eas caused by punched-through reinforcement bars seal themselves, whereby a virtual self-healing effect is given.