Title: Failure of Over-Reinforced Hybrid Fiber Reinforced Polymer Concrete Beam Columns

Author(s): A. Mirmiran, M. Shahawy, and C. El Khoury

Publication: Symposium Paper

Volume: 188

Issue:

Appears on pages(s): 125-134

Keywords: columns; core; ductility; durability; fiber reinforced polymer; high-strength concretes; tubes

DOI: 10.14359/5616

Date: 8/1/1999

Abstract:
Concrete-filled fiber reinforced polymer (FRP) tubes provide an alternative to conventional reinforced and prestressed concrete columns. The tube helps turn normal strength concrete core into a high performance concrete, i.e., one with high strength, ductility, and durability. The over-reinforcement in concrete-filled tubes helps avoid split rupture of the FRP reinforcement in tension, which is catastrophic in nature. A total of 8 concrete-filled FRP tubes were tested as beam-columns under a combination of axial and flexural loads. The tubes were 9 feet long, and had an outside diameter of 13 11/16 in. with a wall thickness of about 0.55 in.. The study showed that over-reinforced concrete-filled FRP tubes generally behave well as beam columns. They deflect to a lesser extent than the corresponding under-reinforced sections. They are also more efficient than under-reinforced sections, because a smaller portion of their sectional capacity is consumed by secondary moments and P-D effects. Their failure, while in compression, is considered to be gradual and progressive.