Title: Novel Shear Reinforcement for Fiber-Reinforced Polymer-Reinforced and Prestressed Concrete

Author(s): Paul Arthur Whitehead and Timothy James Ibell

Publication: Structural Journal

Volume: 102

Issue: 2

Appears on pages(s): 286-294

Keywords: fiber-reinforced polymer; prestress; shear

DOI: 10.14359/14280

Date: 3/1/2005

Abstract:
For fiber-reinforced polymer (FRP) materials to proliferate as internal reinforcement and prestressing tendons for concrete structures, they should be used rationally, lest the indisputable advantages that these materials possess be lost due to poor design. This paper presents the findings of research conducted into the shear behavior of FRP-reinforced and FRP-prestressed concrete beams containing continuous FRP helical transverse reinforcement. Twelve tests were conducted on ordinary reinforced beams and 15 on FRP-prestressed concrete beams. The results showed that full-depth unbonded rectangular helixes were more effective than unbonded circular helixes for equal quantities of material. A fully-bonded full-depth helix system, combined with a fully-bonded compression-zone circular helix system, led to considerable deformability and ductility. It is suggested that this configuration produces high shear capacity and genuine plastic-based ductility during shear collapse. Comparisons between experimental results and existing design guideline predictions are presented, demonstrating the conservative nature of the ACI-440.1R-03 shear clause.