Fatigue Performance of Corroded RC Beams Strengthened With Prestressed AFRP Sheets

A primary study on fatigue behaviors of strengthening corroded RC beams using prestressed aramid fiber reinforced polymer(AFRP) sheets with permanent anchor was carried out.The objective is to examine the effects of AFRP composite rehabilitation systems on the fatigue performance of corroded RC beams.Based on the fatigue experimental results,the effects of different pre-stress level of AFRP sheets under different ratio of corrosion(moderate corroded:reinforcement mass loss is 6.0%,severe corroded:reinforcement mass loss is 12%) on the properties of the fatigue failure, fatigue life, mid-span deflection and materials strain were analyzed. The experimental results showed that, the fatigue failure mechanism of the corroded RC beams strengthened with AFRP sheets is the fatigue fracture of steel bar. Comparison between the beams strengthened with prestressed AFRP sheets and the beams with non-prestressed AFRP sheets was made, and it shows that the fatigue life of the retrofit RC beams increased with increase of the pre-stress level of AFRP sheets and the fatigue life of the corroded RC beams decrease with increase of the ratio of corrosion. Pitting corrosion resulted in the increase in the fatigue notch factor, and this increase resulted in a significant reduction in the fatigue life.