Probabilistic assessment of FRP-confined reinforced concrete columns

This paper presents a reliability study on reinforced concrete (RC) columns retrofitted by Fibre Reinforced Polymers (FRP) confinement. First, variability of the compressive resistance of FRP-confined RC columns considering uncertainty in the model error, material properties, section dimensions, FRP strain efficiency factor and minimum load eccentricity as well as any existing correlation among random variables was studied. Then, reliability of FRP-confined RC columns designed based on the ACI 440 and the fib bulletin 14 guidelines was investigated. Results showed that in order to achieve the target reliability used in design of conventional RC columns, resistance reduction factors of these guidelines require modification. For the design of FRP-confined RC columns, a resistance reduction factor of 0.85 for the ACI 440 guideline and a partial safety factor of 1.45 for the fib bulletin 14 are suggested.