Unidirectional Core-Shell Hybrids for Concrete Reinforcement - A preliminary Study

Abstract

Fiber-reinforced plastic (FRP) bars are currently being used to replace steel bars as concrete reinforcement. For non-prestressed applications, these FRP bars exhibit a relatively low modulus of elasticity and a lack of ductility. This report shows that two-fiber hybrid composites can be optimized to obtain a rebar with a modulus of elasticity equal to steel, as well as a pseudo-plastic behavior. This pseudo-plastic behavior corresponds to the gradual transfer of the load from the low-elongation fibers being ruptured to the high- elongation fibers. Hardening characteristics can be obtained which allow for a gradual fiber rupture. By placing the low-elongation fibers in the center of the rebar, and by winding the high-elongation fibers as a helical shell around this core, higher rebar strains to failure can be obtained. The ratio of the rebar failure strain to the rebar yield strain can be enhanced by increasing the shell fiber's angle with respect to the rebar longitudinal axis. FRP, Rebar, Concrete, Fibers, Carbon fibers, Glass fibers, Hybrids, Reinforcing bar.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1994
Accession Number
ADA277045

Entities

People

  • L. J. Malvar

Organizations

  • Naval Facilities Engineering Service Center

Tags

Communities of Interest

  • Air Platforms
  • Engineered Resilient Systems

DTIC Thesaurus Topics

  • Bearing Strength
  • Biocomposites
  • Composite Materials
  • Elastic Properties
  • Engineering
  • Fibers
  • Material Degradation Processes
  • Materials
  • Materials Laboratories
  • Materials Science
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Poisson Ratio
  • Reinforced Plastics
  • Resistance
  • Stress Strain Relations

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Pavement Materials Engineering.
  • Reinforced Composite Materials