Title: Concrete Encased in Fiberglass-Reinforced Plastic

Author(s): Michael N. Fardis and Homayoun Khalili

Publication: Journal Proceedings

Volume: 78

Issue: 6

Appears on pages(s): 440-446

Keywords: beams (supports); columns (supports); composite construction (concrete and plastic); compression tests; confined concrete; cylinders; ductility;flexural strength; glass fibers; plastic forms; strength; tensile strength.

DOI: 10.14359/10527

Date: 11/1/1981

Abstract:
Fiberglass-reinforced plastics (FR P) ha ve very high tensile strength but relatively low modulus and poor stability in compression. It is proposed to construct FRP plain concrete composite members, in which an FRP casing is used as a form that stays permanently with the member, confining the concrete and acting as tensile reinforcement. Such a combination can result in significant savings in material and construction costs. Circular FRP-encased concrete cylinders tested in concentric compression exhibit very high strength and ductility. Rectangular FRP-encased concrete beams were constructed also with varying amounts of unidirectional FRP reinforcement added at the bottom. Such beams have very good strength and ductility, and their deflections are almost completely reversible, even after loading to their peak capacity, provided that enough FRP reinforcement has been added at the bottom to prevent brittle failure by fracture of the FRP in tension.