The long span precast concrete beam null which possesses the hollow section in the span

摘要

PURPOSE:To reduce the weight of beams, the cross-sectional area of parts, and bulkiness of parts by a method in which a U-shaped steel frame with opened upper end is integrally buried in the central part by leaving the longitudinal both ends of a precast concrete beam. CONSTITUTION:The fixed end la of the beam lower end main bar 1 is projected from both ends of the longitudinal direction, and the upper part of web bars 2 is projected from the deficient portion of slab cross section. By leaving the longitudinal both ends of the beam A, a U-shaped steel frame 3 with opened upside is buried in the central part. A shear resistant part such as stud dowel 4 is welded to the periphery of the frame 3 to integrate it with the beam concrete, and the stud dowel 4 is welded to the inner surface of the frame 3 to integrate it with the following concrete. A concrete-stop plate consisting of perforated plates such as metal lath is set on both ends in the longitudinal direction of the frame 3. The weight of parts can thus be reduced and economical advantage can also be raised.