ULTIMATE FLEXURAL CAPACITY OF REINFORCED CONCRETE BEAMS STRENGTHENED WITH CFRP PLATES FOR DIFFERENT UNLOADING CONDITIONS

The capacity of reinforced concrete beams can be deficient due to a variety of factors. The external bonding fiber reinforced plastic is thought to be a promising strengthening method for its high strength, light weight, minimum effect on headroom, and ease of construction and maintenance. Based on the assumption of plane section, a method for calculating the ultimate capacity of reinforced concrete beam strengthened with carbon fiber reinforced plastic (CFRP) plates is presented in this paper considering the effect of secondary loading for different unloading conditions. The calculation capacities of strengthening beams show satisfactory agreement with the experimental results.