Flexural durability of FRP bars embedded in fiber-reinforced-concrete

• Long-term flexural performances were investigated by accelerated aging test.
• Concrete degradation was the main reason for the flexural degradation.
• Adding fibers to concrete showed more than 30% increase in the ductility index.
• All the beams tested satisfy the minimum ductility index requirement of 4.

This paper presents the results of the long-term flexural behaviors of a hybrid system consisted of continuous fiber-reinforced-polymer (FRP) rebar and fiber-reinforced-concrete (FRC). Flexural durability for the FRP/plain concrete system that served as a reference is also reported. Test results indicated that the ultimate flexural strength and ductility experienced minor reduction when exposed to combined environmental conditioning, including freeze–thaw cycles, high temperature (60 °C), and de-icing salt solution. The degradation of concrete may be the main reason for the flexural strength degradation. The addition of fibers with a volume fraction of 0.5% improved the flexural behavior by increasing the ductility level by more than 30%, when compared to the companion beam, for both unweathered and weathered beams. After being subjected to the environmental conditioning, ductility indices for all the tested beams were still above the minimum requirement of 4.