Title: Performance of Glass Fiber-Reinforced Polymer Bent Bars

Author(s): Natasa Jeremic and Shamim A. Sheikh

Publication: Structural Journal

Volume: 118

Issue: 2

Appears on pages(s): 273-285

Keywords: bent bars; corrosion; creep; durability; glass fiber-reinforced polymer (GFRP); stirrups; sustained load

DOI: 10.14359/51729349

Date: 3/1/2021

Abstract:
Corrosion-resistant glass fiber-reinforced polymer (GFRP) bars have been growing in popularity as an alternative to steel reinforcement. This study investigated newly developed GFRP bent bars for strength reduction of the bends in relation to the straight portion, as well as their long-term behavior under sustained load. Two test methods were used to determine the bend strength, consisting of 24 stirrups in the standardized testing procedure, and 10 bent bars in the shape of a “J” in a modified direct tension pullout test. The bend strength ranged from 35 to 55% of the straight portion. Additionally, sustained load tests were carried out on eight stirrups to estimate the stress level the bars could sustain for a 100-year service life. This stress, extrapolated from a logarithmic creep equation developed from regression analysis of the test results, was found to be close to 50% of the instantaneous strength.