METHOD AND MATERIALS FOR BUILDING ROAD AND AIRFIELD PAVEMENTS WITH CAST VIBRATION-COMPACTED ASPHALTIC-CONCRETE MIX Russian patent published in 1998 - IPC

FIELD: motor road building technology. SUBSTANCE: this relates to building and overhaul repair of pavements on high-category motor roads and runways of airfields. According to method, placed and vibration-compacted by asphalt spreader is specially designed cast asphaltic-concrete mix. Embedded in still hot pavement surface is crushed stone of 3-10 mm size treated with bitumen. Cast asphaltic-concrete mix with flowability at 200 C being not less than 25 mm is placed at temperature of 190-210 C. Used in mix is crushed stone with fraction size up to 20 mm with content of powder and clayey particles of up to 5 mass% made from hard-to-polish rock or gravel, also used is natural sand with content of powder particles up to 5 mass% or artificial sand produced by crushing with content of powder particles up to 9 mass%. Also used is bitumen with softening temperature not below 51 C and flash point not below 240 C. Proportioning of aforesaid components in asphaltic-concrete mix is as follows, mass%: 5-10 mm crushed stone 41.0-49.0; mineral powder 13.0-19.0; bitumen 6.4-8,0; sand - the balance. Composition of cast vibration-compacted asphaltic-concrete mix is designed with taking into consideration conditions of building and expected operation of pavement, properties of bitumen, crushed stone, sand and mineral powder. Proportioning of components is calculated basing on total content in mix of mineral particles smaller than 0.071 mm and of 5-20 mm crushed stone with taking into account relative density of its pieces in framework of cast asphaltic-concrete mix. Basing on content of 5-20 mm crushed stone, determined is content of sand proceeding from optimal mass relation of 0.14-5 mm sand and 5-20 mm crushed stone in process of vibration compaction. Content of mineral powder is calculated basing on given total amount in mix of bitumen and all mineral particles smaller than 0.071 mm. Amount of bitumen is determined as difference between 100% of mass and content of all mineral components. Ready asphaltic-concrete pavement built by aforesaid method and low-grade materials with use of standard equipment fully meets corresponding requirements. EFFECT: higher efficiency. 2 cl, 6 tbl