New Model for Analytical Predictions on the Bending Capacity of Concrete Elements Reinforced with FRP Bars

Many studies on Fibre-Reinforced Polymers Reinforced Concrete (FRP-RC) beams tested in flexure have been performed by various researchers around the world. This work presents the results of statistical and mathematical analyses based on experimental data; 102 samples were collected and supplemented from 16 different scientific papers. The load capacity of the beams determined on the basis of the tests was compared with the load capacity calculated on the basis of the recommendations of ACI 440.1R-15. The results obtained from experimental studies showed that for 91.4% of the samples, the underestimation of the load capacity on average was equal to 15.2% of theoretical, and for 33.3% of the beams, the load capacity was overestimated by 26.7%. The paper proposes a new empirical coefficient incorporating material parameters to be implemented into ACI 440.1R-15 flexural design approach in order to improve the accuracy of this model in scope of the nominal flexural strength capacity of FRP-reinforced beams estimation. Modifications to flexural design of FRP-RC beams with the use of ACI 440.1R-15 design code were proposed. As a result, the reliability of the analytical model is increased; therefore, the new model guarantees higher safety and cost efficiency of designed concrete structures reinforced with FRP bars.