Effect of applied stress and bar characteristics on the short-term creep behavior of FRP bars

This paper presents the creep behavior of various FRP (GFRP, CFRP, and hybrid) bars in order to investigate the effects of different parameters, including the applied stress levels, bar diameter, and the type of fiber and resin in the creep behavior of FRP bars. The creep strains versus time curves were experimentally obtained for 83 days. Moreover, a statistical study, including analysis of variance (ANOVA) and linear Bayesian regression was conducted to investigate the contribution of the studied parameters. The results showed that in GFRP bars the ratio of ultimate creep strain to the initial elastic strain decreased when the applied stresses on the bars exceeded 30% of their ultimate tensile strength. In CFRP bars, the creep ratio decreased by increasing the applied stresses continuously. In addition, it was observed that the GFRP bars were more creep resistant in comparison to CFRP bars and CFRP bars with vinyl ester resins were more creep resistant than those with epoxy resins. (C) 2018 Elsevier Ltd. All rights reserved.