DEVICE FOR PREVENTING AIR LOCKS IN THE COURSE OF MORTAR INJECTION Russian patent published in 2002 - IPC

FIELD: construction engineering. SUBSTANCE: device is used in manufacturing reinforced concrete structures with large spans of 30-100 m for bridge engineering. It functions to prevent air locks in making ducts for reinforcement being stressed and is essentially pipe whose interior communicates with atmosphere on one side and with duct-former hole ensuring air evacuation from duct interior during injection of hardening mortar into it on other side. Top part of pipe mounts its shutoff device in the form of gate valve that closes as soon as hardening mortar starts flowing out of it. Strap made in the form of semi-cylinder with nozzle enclosing at least one third of duct-former throughout perimeter is arranged between pipe and duct-former; pipe is inserted in a spaced relation relative to duct-former through depth exceeding diameter of the latter. Ribs forming labyrinth packing together with duct-former corrugations may be made on semi-cylinder surface facing duct-former; gaps are sealed by adhesive tape over perimeter of semi-cylinder edges; diameter of pipe is minimum 12 mm or 0.06-0.8 of duct-former diameter. EFFECT: enhanced reliability of mortar injection in ducts. 3 cl, 2 dwg