Flexural performance of concrete beams reinforced with FRP bars grouted in corrugated sleeves

Abstract

This paper proposed to use high-strength grout and corrugated sleeves to hold FRP bars in tension zone of concrete beams, aimed at reducing crack width and improving serviceability performance. Ten large-scale simply supported beams measuring 200 mm wide, 400 mm depth, and 4000 mm length, were tested under four-point bending. One reference beam was reinforced with steel bars and four beams were reinforced with FRP bars. Other five beams were reinforced with FRP bars grouted in sleeves in the tension zone. Test results are discussed in terms of failure modes, deflection and cracking behavior. FRP-RC beams failed by concrete crushing, achieving higher flexural capacity and larger deflection than the steel-RC beam. The use of FRP bars grouted in corrugated sleeves in tension zone of beams was an effective way to reduce crack widths and improve serviceability performance. The average bond-dependent coefficient (kb) for grouted FRP bars in sleeves was 38% lower than FRP bars surrounded by concrete. The maximum crack width at service load, which accounted for variability of crack width and long-term effect of sustained load, was less than the crack width limit of 0.7 mm for beams with grouted FRP bars in sleeves but not for beams only with FRP bars.