| 摘要 |
1477351 Bituminous granulates SOC CHIMIQUE ROUTIERE ET D'ENTREPRISE GENERALE 9 May 1974 [10 May 1973] 20470/74 Heading C3N A process for preparing a composition for the surface of roads, airport runways, canals and dams comprises mineral granulates coated with 4-12% by weight, with respect to the weight of the granulates, of a binder consisting of 93-96% by weight of fluxed coal pitch or fluxed tar and 4-7% by weight of a homopolymer or copolymer of vinyl chloride, wherein the homopolymer or copolymer is mixed rapidly in a mixer in the form of a powder having a particle size of less than 100 microns, e.g. 2-10 microns, with the granulates previously heated to a temperature between 120‹ and 160‹ C. and the fluxed coal pitch or tar is thereafter introduced into said mixer with continued mixing. The polymer used is preferably polyvinyl chloride or a copolymer of vinyl chloride and vinyl acetate. In the specific examples the aggregates are based on gravel, crusher sand, river sand, calcareous filler and round sand. The duration of the rapid mixing of the granulates and homopolymer or copolymer is 5-20 seconds. The granulates may be heated to 130-160‹ C. before the introduction of the homopolymer or copolymer and the total time of mixing may be 40 to 90 seconds.
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