Design Guidelines and Standards

There are a number of authoritative consensus design guidelines for the designer to follow. Generally the design methodology for FRP reinforced concrete members follows that of steel reinforcing but taking into account the linear elastic or non-ductile nature of the material with different safety factors. Care is taken to avoid the possibility of a balance failure mode where concrete crushing and rupture of the bar could occur simultaneously. The designer must choose between compression failure of concrete, which is the preferred mode, and rupture of the FRP bar with a higher factor of safety.
The use of a consensus design method, rather than a proprietary derivation from existing design methodologies, helps protect the engineer of record and allows for multiple bidders for a given project.

ACI committee 440 is the most authoritative and prolific consensus standards body involved in the publication of design guidelines for the use of FRP bars.

Hughes Brothers has been an active participant in 440 committee activities since 1994. Committee 440 documents are based on research performed world-wide.

Design with Aslan 100 GFRP bars is dictated by ACI 440.1R-06, "Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars".

This third iteration document, can be purchased from the ACI International bookstore (linked by this text) $70.50 for non-members and $43.00 for ACI members. This document and all other ACI 440 publications are included in the "Manual of Concrete Practice" which many engineering firms obtain.

Material properties of FRP bars are validated with a complete set of test methods from ACI. Document 440.3R-04 "Guide Test Methods for Fiber Reinforced Polymers for Reinforcing or Strengthening Concrete Structures".

ASTM committee D30 is transitioning the 440 test methods to individual ASTM test methods such as ASTM D7205 "Tensile Properties of Fiber Reinforced Polymer Matrix Composite Bars".

The Canadian Highway Bridge Design Code, CSA-S6-06, adopted provisions for the use of FRP bars in 2006. As a result of this, many bridges and parapets in Canada are being built using FRP bars including some very substantial structures such as the Floodway Bridge pictured below.

In 2008, ACI committee 440 published "Specifications for Construction with Fiber Reinforced Polymer Reinforcing Bars" document 440.5-08. Written in mandatory language, this document offers guidance to the contractor and site inspector describing limitations and allowances for the delivery storage, handling, fabrication, bar placement, field repair and cutting and concrete placement for projects incorporating the use of Aslan FRP bars.

A companion document to the "Construction Specifications" is the 440.6-08 "Specifications for Carbon and Glass Fiber-Reinforced Polymer Bar Materials for Concrete Reinforcement". This document describes the minimum permitted constituent materials, limits thereof, minimum performance requirements for carbon and glass FRP bars.
This document essentially is the reference standard a designer would use to ensure materials procured for their design would be furnished in accordance with design performed by the 440.1R-06 guidelines. At this time, this is the closest thing to an ASTM A619 type specification for FRP bars.
All Aslan FRP bars meet or exceed the material properties of 440.6-08.

In November 2009, AASHTO published "AASHTO LRFD Bridge Design Guide Specifications for GFRP Reinforced Concrete Decks and Traffic Railings including a Commentary" based on the work of committee T-6. This document gives the American bridge design community some conservative guidelines for implementation of GFRP rebar in decks and railings.

In Canada, the use of FRP bars in buildings is dictated by the code CSA S806-02.

CSA S-807 Specification for Fibre-Reinforced Polymers.This specification offers guidance in terms of limits of constituent materials for FRP bars, criteria for qualification of FRP bar systems, manufacturers quality control reporting and owners acceptance criteria. The specification provides a framework for owners to use to pre-qualify FRP bar suppliers for bidding on major public works projects and for the manufacturers reporting of specific, traceable production lot properties and acceptance limits.

In Europe, the Federation Internationale du Beton FIB Task Group 9.3 has published a technical report "Bulletin 40", which is a "state of the art" of FRP reinforcement in RC structures. Work is under way on provisions for FRP bars in EuroCode 2 format. Norway and Italy have published internal design codes for the use of FRP bars.

To aid the designer unfamiliar with the various FRP design guides and standards, Hughes Brothers has engineering assistance available in house. Our staff of engineers are intimately involved in the authorship of the various design guides, standard and test methods and are available to help with your specific project.

We will NOT stamp designs, rather we are here to "compliment" your efforts for a successful implementation of Aslan FRP bars.

Using industry standard consensus design methods, we will furnish you with a design proposal based on the inputs you provide us. Hughes Brothers will not perform any structural analysis and our scope is limited to design advice only to the engineer of record concerning implementation of Aslan FRP bars.

To assist you, our staff needs a clear understanding of:
- Geometry of the concrete member -- electronic or CAD drawings are most helpful
- Moment and shear forces the member is subject to
- Concrete strengths