Bituminous capping and sealing layer for permanent structures - of hot poured polymeric poly:olefinic bitumen with embedded reinforcement and topping of hard mineral granules

摘要

Bituminous sealing and capping layer for permanent structures and which provides a heat shield, comprises a layer of polymeric polyolefinic bitumen with a softening point of greater than or equal to 120 deg.C, a reinforcement embedded in the bitumen, and an outer layer of hard mineral granules. Pref. the layer comprises 2-4 kg/m2 of the polymeric polyolefinic bitumen, 2-4 kg/m2 mineral granules and 50-500 g/m2 of the reinforcement. The mineral granules are esp. quartz type silica or milled stone with a particle size of 1-4 mm, esp. 1-2 mm. The reinforcement is esp. of non woven polyester fabric, or glass fabric. The layers can be applied directly e.g. to concrete substrates on permanent structures such as bridges. The layers allow easy escape of water vapour during hot pouring of the bitumen, so that good adhesion of the layer is obtd. without using intermediate layers e.g. of kraft paper as in prior art processes. The layers have high strength and provide a good heat shield for the substrate. A normal bitumen surfacing layer may be applied over the sealing layer of the invention, in which case good adhesion of the upper bitumen layer is obtd.