BITUMEN COMPOSITION AND WATER-RESISTANT SHELL Russian patent published in 1997 - IPC

FIELD: bitumen-based products. SUBSTANCE: emphasis is specifically placed on bitumen compositions for paving streets and for manufacturing water-resistant shells of various types. Composition contains bitumen, polyethylene and/or secondary polyethylene with density 0.870-0.970 g/ml and melt flow factor 20-70, ethylene-vinylacetate copolymer and/or secondary ethylene-vinylacetate copolymer with melt flow factor from 0.3 to 500 and vinylacetate content 1-50%, and also polyethylene wax with molecular weight 3000-6000. Polyethylene to bitumen weight ratio is (1-30):100. Weight ratio of ethylene-vinylacetate copolymer to polyethylene plus ethylene-vinylacetate copolymer is (1-50):100, and percentage of wax in total polymer mass ranges from 1 to 40%. Bitumen characterized by permeability value 40-300 dmm in conformity with ASTMD-36 is obtained through vacuum distillation. Target additives may also be included. Description of water-resistant shell is provided which contains a layer based on composition of invention, reinforcing layer, and additional layers of organic and/or inorganic materials. Reinforcing layer is made of felt and fabric that can be nonwoven one and based on polyester and glass fibers. Thickness of layers in water- resistant shell is 2-8 mm. EFFECT: widened diversity of properties of bitumen-based materials. 12 cl, 4 tbl