Reliability analysis of concrete beams reinforced with FRP bars

Abstract

The strength reduction factors (ϕ) adopted by ACI-440.1R-15 standard code for the flexure design of Fiber Reinforced Polymers Reinforced Concrete (FRP-RC) beams are calibrated in this study. The code calibration process aims to achieve a particular target reliability index (β_T) for the selected FRP-RC rectangular beams. An extensive experimental database is collected and used in the calibration process of the resistance factors. It was found that the calibrated ϕ led to a more economical and less conservative design while satisfying the safety requirements imposed by the design code. To meet the β_T, a recommended value of ϕ, is found to be 0.70 for cast-in-situ beams failing in compression and 0.65 for tension-controlled cast-in-situ beams. Thus, the proposed values are slightly greater than comparable factors adopted by the ACI code of 0.65 for compressioncontrolled and 0.55 for tension-controlled cast-in-situ beams.