| 摘要 |
PURPOSE: A manufacturing method of a compound prestress composite beam using a concrete filling steel pipe is provided to prevent external damage by preventing the exposure of concrete to the outside, to increase the strength of concrete, to reduce stiffeners of reinforcing bars or distribution bars and to secure simplicity on construction by excluding a concrete form on manufacturing. CONSTITUTION: A manufacturing method of a compound prestress composite beam using a concrete filling steel pipe comprises the steps of: forming a rectangular pipe(22) in a lower flange(21) of an I-shaped beam(20); provoking residue deformation by residual stress and removing load at the state of applying a primary preflection load decided to make maximum bending stress of a shape steel beam below the elastic critical stress; installing a sheath pipe(25) inserting a tendon into the pipe(22) of the lower flange(21); supporting both ends of the I-shaped beam(20) and compressing, placing and curing mobile concrete in the pipe(22) of the lower flange(21) at the state of applying the same secondary preflection load as the primary preflection load; removing the secondary preflection load; and applying third preflection load to increase bending moment of the shape steel beam in 10¯20 percents more than design maximum bending moment by combining with the secondary preflection load by pulling out the tendon inserted into the sheath pipe(25) by and fixing to both ends of the shape steel beam.
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