Impermeable sheets of partially impregnated nonwoven fabric - to inhibit rupture by crack propagation from faulty substrates

摘要

Impermeable covers 0.5-5 mm thick comprising a fabric coated on one or both faces with a layer of impermeable material which only partially impregnates the fabric structure, to leave a core stratum of the fabric free from impregnation. Used for mfr. of covers for lining reservoirs, sealing walls, damp course layers for foundations etc. For paved areas, the covers may be overlaid with a thin layer of filled resin or by slabs of concrete, opt. faced on their underside with a layer of insulating material. Covers may be=5 m wide. The core layer interrupts crack propagation through the cover and across the outer impermeable layer, e.g. if the substrate cracks, e.g. due to shrinkage of concrete The fabric is a non-woven material based on natural or synthetic fibres, pref. of 'BIDIM' (RTM-Rhone-Poulenc polyester). The coating material may be deposited from an (aqueous) emulsion, pref. 'DAKFILL' (RTM). Covers may carry a top dressing of filled resin 2-3 mm thick, specifically of 'MATCODAL' (RTM).