Title: Non-Hooped Reinforced Concrete Columns and Beam-to-Column Connections Laterally Confined in Bellows Square Steel Tube
Author(s): M. Tomll
Publication: Symposium Paper
Appears on pages(s): 375-396
Keywords: beams (supports); columns (supports); reinforced concrete; earthquake-resistant structures; shear properties; steels; Structural Research
The method of transversely reinforcing columns and beam-to-column connections with bellows square steel tubes was devised to develop a construction method necessary to realize reinforced concrete frame highrise buildings which are easy to design and execute in zones where high earthquake resisting performance is required. To secure a ductile seismic behavior for columns subjected to heavy load, strong shear reinforcement and transverse reinforcement are necessary to prevent brittle failure, such as shear failure, bond split failure along the longitudinal bars, and failure of the compressed extreme fiber of concrete, or to change it into ductile failure. It was manifested by concentric compression tests of 1/4 scale columns, combined compression, bending and shear tests of 1/3 scale columns, seismic load tests of 1/3 scale and 1/4 scale beam-column subassemblages, and bond tests of main bars embedded in 1/4 scale columns that no dangerous collapse of the building is likely to occur even if shear forces of some of the columns and/or beam-to-column connections in the same story reach the loading capacity, because the mechanical behavior of the columns and beam-to-column connections is very ductile even when the webs of their tube yield in shear. Field execution tests of this structure have been conducted.