Reliability of Compression-Controlled FRP RC Flexural Members Designed using North American Codes and Standards: Comparison and FRP Material Resistance/Strength Reduction Factor Calibration
Fadi Oudah and Adam Hassan
Appears on pages(s):
structural reliability; reliability-based design; FRP; buildings; bridges; CSA-S6; CSA-S806; ACI440.1R
The use of fiber-reinforced polymer (FRP) in structural engineering applications is challenged by the need for increasing the market competitiveness of FRP as compared with conventional reinforcing materials. The market competitiveness of FRP can be enhanced by optimizing the design provisions of FRP-reinforced concrete elements in relevant design codes and standards using structural reliability methods. The objectives of this research are to (1) evaluate and compare the reliability of compression-controlled flexural concrete members reinforced internally using FRP and designed using the Canadian Highway Bridge Design Code (CSA-S6-19), the Design and Construction of Building Structures with Fibre-reinforced Polymers Standard (CSA-S806-17), and Design and Construction of Structural Concrete Reinforced with FRP bars Guideline (ACI440.1R-15); and (2) recommend FRP material resistance factor and strength reduction factor for the respective codes/standards based on a unified target reliability approach. Reliability analysis using Monte Carlo simulation indicates that the reliability index associated with a flexural design using ACI440.1R-15 is about 20% greater than the average reliability index of similar beam and slab sections designed using CSA S6-19 and CSA S806-17 (equates to 150 times greater probability of failure for sections designed using CSA S6 and CSA S806). The recommended material resistance factors for CSA S6 and CSA S806 and the strength reduction factor for ACI 440.1R based on the reliability analysis conducted in this research are 0.80, 0.85, and 0.75, respectively, for a unified target reliability indexes of 4.0 and 3.1 for beams and slabs, respectively. Structural designs based on the recommended values yield consistent reliability indexes among the three codes/standards.