Design Codes

Designing with Composite Rebar

The general design recommendations for flexural and shear concrete elements reinforced with FRP reinforcing bars are presented in ACI 440.1R-15 “Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars,”, as reported by the American Concrete Institute (ACI) committee 440.  Generally, the design methodology for FRP-reinforced concrete members follows that of steel reinforcing, but takes into account the linear elastic or non-ductile nature of the material by using an FRP material reduction factor, and controlling the stress and strain at the serviceability limit state.

The design philosophy adopted for FRP bars allows consideration to be given to either 1) FRP rupture or 2) concrete crushing as the mechanism that controls failure.  It is based on limit states design principles.  An FRP-reinforced concrete member is designed based on its required strength, and then checked for serviceability criteria.  In most cases, serviceability criteria limits will control the design.

Design engineers should consider the appropriateness of reinforcing concrete with FRP rebars keeping in mind the following basic points in their designs:

Design Codes/Guidelines

Extensive effort on an international level has resulted in the development of codes and guidelines for FRP composite use in reinforced concrete. Existing publications currently available for such use are as follows:

American Concrete Institute (ACI)

Available from American Concrete Institute

American Association of State Highway and Transportation Officials (AASHTO)

Available from AASHTO

Canadian Standards Association (CSA)

Available from Canadian Standards Association

Intelligent Sensing for Innovative Structures - Canada (ISIS)

Available from ISIS Canada

Japan Society of Civil Engineers

International Federation for Structural Concrete

Available from International Federation for Structural Concrete

Italian National Research Council

Available from Italian National Research Council