Title: Glass Fiber-Reinforced Polymer Effectiveness in Field Repair of Piles

Author(s): Shayan Yazdani, Mostfa Al Azzawi, Cesar Quesada Garcia, Gray Mullins, and Rajan Sen

Publication: Structural Journal

Volume: 120

Issue: 1

Appears on pages(s): 31-47

Keywords: corrosion; epoxy; fiber-reinforced polymer (FRP); field repair; polyurethane; steel

DOI: 10.14359/51737230

Date: 1/1/2023

Abstract:
The Friendship Trail Bridge was the site of 13 fiber-reinforced polymer (FRP) repairs of corroding reinforced concrete piles undertaken at three disparate times between 2003 and 2008. Following its demolition in 2016, eight 113 to 129 cm (3.7 to 4.2 ft) long pile segments were retrieved and examined to evaluate the effectiveness of the FRP in corrosion repair. These included two unrepaired control piles and six repaired using two to six layers of epoxy- or urethane-bonded glass fiber-reinforced polymer (GFRP) fabric. Of the six repaired piles, one was repaired in 2004, two in 2006, and three in 2008. The electrochemical properties of the concrete and steel were established, and titration analyses were conducted to determine the acid-soluble chloride content. Sixty-four reinforcing bars were retrieved, and metal loss profiles were obtained from digital measurements taken at 13 cm (5 in.) intervals. There was evidence of the effectiveness of GFRP but large variation in cover and intrusive instrumentation distorted findings, limiting the application of rigorous statistical analysis. The unexpectedly small metal loss in the controls following 60 years of exposure is indicative of the unrecognized role played by marine growth in mitigating corrosion in aggressive marine environments.