| Externally bonding fiber reinforced polymer (FRP) sheets with epoxy matrix is an effective technique for strengthening and repairing reinforced concrete (RC) beams under flexural wads. However, effective methods to evaluate the serviceability of FRP RC beams are not fully understood nor developed yet. A comprehensive analytical method for modeling the strain distribution and stress transfer between materials and crack width in FRP RC beams was carried out in this study. A total of eight beams was tested and analyzed: two were control beams and six were reinforced with carbon fiber reinforced polymer (CFRP) sheets glued by epoxy resin. Double steel reinforcement, different reinforcement ratios and various types of epoxy matrix were used to simulate the variety of conditions. All specimens were subjected to a four-point-bending load while the crack widths and mid-span strains at both compression and tension faces were recorded. Both experimental and theoretical results are presented and compared. The results showed there is a good agreement between the experimental and analytical results. Step-by-step procedures for applying this method and examples using MATLAB based computing programs were also presented. |
