Fatigue performance of RC beams strengthened with CF sheets bonded by inorganic matrix

The objective of this paper is to study the fatigue performance of concrete beams strengthened with carbon fiber sheets bonded with inorganic matrix. Steel reinforced concrete strengthened with 3 layers of carbon fiber sheets were used for this study. The relationship between fatigue strength, fatigue life, crack width, and number of cycles were studied. Results showed that with increasing the number of cycles, the crack width and crack depth increased at about the first half million cycles of loading and thereafter the crack width and depth tended to stabilize. Both load capacity and number of fatigue cycles of RC beams significantly increased with carbon fiber sheets. The fatigue cracks seemed to develop during the first few cycles. The study showed that strengthening RC beams with carbon fiber sheets bonded by inorganic matrix improved fatigue performance and increased fatigue strength. The fatigue strength increased by 55% as compared with control beams.