METHOD OF PRODUCTION OF CAST ASPHALT-CONCRETE MIX Russian patent published in 2004 - IPC

FIELD: road building.

SUBSTANCE: invention relates to road building processes designed for forming strong road coating and it can be used at repairs of roads under any weather conditions. According to proposed method breakstone of metamorphic sedimentary rock is prepared, mass percentage being 30 to 50%, with sizes of fractions from 5 to 20 mm, break screenings, sand and bitumen with flash point of 240^oC, softening temperature not less than 48^oC and mixing temperature from 140 to 190^oC are taken. Temperature of mineral powder is form 120 to 140^oC. Mineral materials are preliminarily metered out and dried in drying drum by heat of combustion gas. Then mineral materials are delivered along hot elevator for sizing to screen of mixing set, are separated into fraction, and each fraction is delivered into separate compartment of hot hopper. Intermediate storing of mineral materials in hot hoppers is provided. Simultaneously mixing and intermediate storing of bitumen in bitumen tanks is provided. Then components of asphalt-concrete mix in weighing hopper are metered out and current checking of composition of asphalt-concrete mix is carried out. Contaminated flows of air with particles of dust getting out of drying drum and screen are sucked by smoke sucker into cyclones, and entrapped dust is delivered into hot elevator and further on with mineral materials, to screen. Components of asphalt-concrete mix are mixed uniformly at maximum possible enveloping of mineral materials with layer of binding component. Temperature of mixing of cast asphalt-concrete mix in mixer is 300-320^oC and time of dry mixing of materials is not less than 60 s, and time of second mixing cycle with hot bitumen is 60 s, said period is interrupted by sample taking intervals for determining movability of asphalt-concrete mix without loss of mixing temperature by its components. Asphalt-concrete mix from mixer is fed into hopper of skip hoist and then into hopper-accumulator, and ready asphalt-concrete mix is discharged through hydraulic gate from hopper-accumulator into bodies of trucks.

EFFECT: improved process characteristics at production of asphalt-concrete mix.

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