Title: Durability of FRP-Concrete Bond in FRP-Strengthened Bridges

Author(s): Nemkumar Banthia, Aidin Abdolrahimzadeh, Marc Demers, Aftab Mufti, and Shamim Sheikh

Publication: Concrete International

Volume: 32

Issue: 8

Appears on pages(s): 45-51

Keywords: bridges, FRP, strengthening, bond, durability, infrared thermography

DOI:

Date: 8/1/2010

Abstract:
After years of service, the durability of FRP-concrete bond in structures strengthened using FRPs remains uncertain. To investigate the durability of FRP-concrete bond, four in-service bridges in Canada strengthened using externally bonded FRPs were studied. To measure the integrity of the bond, mechanical pull-off tests were performed. In some cases, infrared thermography was used to detect debonding. Results indicate that thermography is an excellent way of detecting debonding between FRP and concrete. Bond is noted to be strongly influenced by the placement technique, exposure severity, location on the bridge, and type of loading. Generally speaking, while the bond in most instances is fairly good, in some cases, a severe deterioration in bond has occurred. This is a cause for concern.