PRESTRESSED COMPOSITE BEAM WITH GRADUAL PRESTRESSING AND PRODUCTION METHOD THEREOF

摘要

PURPOSE: A prestressed composite beam and its production method are provided to maintain a design allowable compression stress by gradually prestressing. CONSTITUTION: An I-shaped beam having an upward lifting amount is produced. Maximum load is given to the I-shaped beam up to allowable stress. Lower casing concrete is poured and cured in a lower flange(20) of the I-shaped beam. Supporting beams(11) are installed on both sides of an upper flange(30) in the I-shaped beam. A tendon(40) is installed in the supporting beam by stressing the tendon and completely removing the maximum load. The lower casing concrete is prestressed primally. The second prestressing is induced by removing the tendon. Concrete is poured and cured in the upper flange and a belly of the I-shaped beam.