Waterproof layer esp. for gun applied concrete tunnel lining - has mesh reinforced central impermeable plastics core and tangled fibre facings

摘要

A method of securing tunnels against inflow of water is intended esp. for structures having gunned concrete linings. Before the concrete lining is applied the tunnel wall is covered with a mat comprising a water-impermeable core layer having on the one side bonding elements for concrete and on the other side spacer elements to keep the mat at a predetermined distance from the tunnel wall. The bonding elements for the gunned concrete and also the spacer elements are pref. layers of tangled non-woven fibres, esp. highly tangled thermoplastics fibres of 1 mm diameter bonded at their crossing points. Fibres may be of polyethylene or polypropylene. The central layer may be a slab of plastics reinforced with a mesh.