Bridges

Cover of Incorporating ACI 440.8 into AS 5100.5 for FRP Strengthening Via M80 Upgrade Project Case Study
Incorporating ACI 440.8 into AS 5100.5 for FRP Strengthening Via M80 Upgrade Project Case Study
  • Publication no: ABC-DES203-14
  • Published: 22 October 2014

As bridges age and standards evolve, it has become increasingly necessary to strengthen existing bridges as a much cheaper option than replacing bridges as a whole.

Carbon fibre strengthening of bridges has become more common in the past 10 years as the cost has become less prohibitive. This paper investigates the application of fibre reinforced polymer (FRP) in Australia via a case study where KBR was the lead designer for Fulton Hogan on the VicRoads M80 Upgrade Project – Edgars Road to Plenty Road.

The scope of this project included attachment of carbon fibre to strengthen these structures according to the ACI 440.2R Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (2008). While this guide is appropriate for the design of FRP strengthening of bridges, it does not seamlessly fit into the design framework of AS 5100.5.

A design methodology was developed to incorporate the FRP load capacities according to ACI440.2R into the framework of AS 5100.5 that considers the following aspects:

  • moment capacity
  • shear capacity
  • shear torsion interaction
  • Vumax comparisons.

Additionally, a method was developed for obtaining additional strain capacity via anchorage of FRP using research results from the strengthening of the West Gate Bridge in Melbourne.