METHOD AND FORM FOR PRODUCING PRESTRESSED REINFORCED CONCRETE ARTICLES Russian patent published in 1998 - IPC

FIELD: construction engineering. SUBSTANCE: according to method, reinforcing rods with end anchors are tensioned in rests installed on working surface of form pan. In this case, in installing reinforcing rods in design position, deforming load is applied to end portions of each reinforcing rod simultaneously at distance of 0.01-0.15 of their length from end faces. This deforming load is directed upwards and perpendicularly to axis of reinforcing rods and at angle of 45-85 deg. to horizontal plane, and this ensures contact of reinforcing rods with rests and position locks which are secured on sides of form. At shortening of reinforcing rods, they are deformed by bending moments from forces of overcenter extension which occurs due to fact that supporting surfaces of rests are inclined at angle which exceeds angle of friction between anchor and surface of rest. For realization of aforesaid method, each rest is fork-shaped in configuration. Height of one of fork teeth exceeds height of another fork tooth by 1.1-8.5 times. Supporting surface of rest is inclined at angle of 4-25 deg. in relation to vertical plane. Surface of lock which is in contact with reinforcing rod or with anchor is displaced horizontally towards smaller fork tooth of corresponding rest by 0.3-1.2 of distance between axes of rest teeth. EFFECT: higher efficiency. 5 cl, 5 dwg