BUNDLED BARS MADE OF HIGH STRENGTH ROPES AND METHOD FOR MANUFACTURING PRE-STRESSED REINFORCED CONCRETE STRUCTURES USING BUNDLED BARS Russian patent published in 2002 - IPC

FIELD: construction engineering; structures of bundled bars; reinforced concrete technologies. SUBSTANCE: bundled bars have anchors installed on their ends and placed in corrugated-surface channel- former and local-reinforcement spiral mounted around end part of bundled bars; inner diameter of channel- former duct exceeds that of circle circumscribed around ducts of bundled bars by at least 1.3 times; anchor cup enclosing bundled bars throughout perimeter is installed on at least one of its end parts and contacts anchor by its one butt-end and by other one joined to adapter made of polymeric material, its section being converging by minimum 1.2 times in direction of anchor cup contacting it; local-reinforcement spiral is mounted around anchor cup and has preferably cylindrical shape, its diameter is minimum 1.1-1.2 of anchor cup length. Method for manufacturing pre-stressed structures with bundled bars involves arrangement of bundled bars made of high strength ropes in corrugated-surface channel-former; installation of anchors and local-reinforcement spiral; laying of concrete mix and tensioning of bundled bars by means of jacks; prior to laying concrete mix bundled bars are placed in corrugated-surface channel-former duct; inner duct of bundle exceeds by at least 1.3 times diameter of circle circumscribed around ducts of bundled bars; anchor cup enclosing bundled bars throughout perimeter is installed on at least one of its end parts and contacts anchor on one end and on other end it is joined to adapter made of polymeric material and having its section converging by minimum 1.2 times in direction of anchor cup contacting it; bundled bars are tensioned by jacks in at least two stages; during first stage force making up 0.2 to 0.3 of design value is applied and as soon as at least design value of force is attained they are held under these conditions for minimum 5 min. EFFECT: improved quality; reduced labor consumption; enhanced reliability and service life. 19 cl, 12 dwg