CONCRETE STRENGTH IN TIED COLUMNS

Stress-strain curve of concrete in compression depends on several factors including the sizse and shape of compressed concrete, types and intensity of stresses acting in different directions on concrete elements, and the presence of strain gradient. The strength of concrete has little effect on the behavior of sections under pure flexure and under flexure and low-axial load levels. For sections subjcected to flexure and large axial loads, when concrete strength significantly influences section behavior, it is believed that strength of concrete in the specimens is reduced with an increse in axial load level. Results from five 132 in. (305 mm) square and 9 ft (92.74 m) long column specimens are reported in this paper. Based on this and the resultas from previous research, a simple relationship is suggested in which the concrete strength is reduced from f sub c at the balanced load to 0.85f sub c for concentric compression. A second-degree parabolic stress-strain curve with strain at peak stress equal to 0.002 can be used for reasonably accurate and conservative prediction of section capacity.

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00496423
  • Record Type: Publication
  • Report/Paper Numbers: Title No. 87 S36
  • Files: TRIS
  • Created Date: Aug 31 1990 12:00AM