Flexural Cracks in Fiber-Reinforced Concrete Beams with Fiber-Reinforced Polymer Reinforcing Bars

Fiber-reinforced polymer (FRP) reinforcing bars have aTtracted considerable 0llellli0l1 for applications where corrosion of steel reinforcement is problemaric. Due 10 rhe generally low elastic modulus and poor bond clwracreristics of FRP as coil/pared 10 steel reinforcing bars, the use of FRP results in IGI:i?er crack widlhs under senJice loads. Fiber-reinforced concrete (FRe) is proposed for use with FRP to reduce crack widths. The work presenred herein includes the resulrs from J6 beams tesred under ./imr-poinr belUiing with either Grade 420 (Grade 60) steel or FRP reinforcing bars, and either plain concrete or FRe. A modified Gergely-Lutz model was applied ro the measured crack widths to calculate bond coefficielJls thar were used to quantify the effixtiveness of FRC in reducing crack widths. In Ihe heal1L~ with steel reinforcing bars, rhe FRC was found 10 have litlle inlluence on crack widths. i/1 rhe beams with FRP reinforcing bars, the FRC was found to significantly reduce maximum crack widths.