Title:
Ductile Hybrid Fiber Reinforced Plastic Reinforcing Bar for Concrete Structures: Design Methodology
Author(s):
Win Somboonsong, Frank K. Ko, and Harry G. Harris
Publication:
Materials Journal
Volume:
95
Issue:
6
Appears on pages(s):
655-666
Keywords:
ductility; fiber reinforced plastic; reinforcing steels
DOI:
10.14359/408
Date:
11/1/1998
Abstract:
This paper addresses the need for a ductile or pseudo-ductile fiber reinforced plastic reinforcement for concrete structures. The criteria to be met by the FRP, which are based on the properties of the steel rebar it is to replace, are threefold: high initial modulus, a definite yield point, and a high ultimate strain. It is shown that the use of a fiber architecture based design methodology facilitates the optimization of the performance of FRP through material and geometric hybrid. Consequently, the advantages of FRP such as high strength, low weight and chemical inertness or noncorrosiveness can be fully exploited. Using the material hybrid and geometric hybrid, it is demonstrated that the pseudo-ductility characteristic can be generated in FRP rebar. Critical material and geometric parameters such as elastic modulus, fiber volume fraction, twisting, crimp, and helical effect in the specimen components were investigated and parametric studies are reported. Ductile hybrid FRP bars were successfully fabricated at 3 mm and 5 mm nominal diameters using an inline braiding and pultrusion process. Tensile specimens from these bars were tested and found to have consistent pseudo-ductile behavior and very good agreement with the analytical predictions.