Size effect on the shear failure of high-strength concrete beams reinforced with basalt FRP bars and stirrups: Fid-Bau Portal

Size effect on the shear failure of high-strength concrete beams reinforced with basalt FRP bars and stirrups

Jumaa, Ghazi Bahroz / Yousif, Ali Ramadhan

Highlights • Investigating the size effect in high-strength concrete beams reinforced with basalt FRP bars and stirrups were conducted. • The size effect on the shear failure of FRP reinforced concrete beams with stirrups could not be eliminated completely. • The ACI 440-15 stirrup strain limit could be relaxed with the condition that the serviceability requirement is satisfied. • An accurate and conservative equation was proposed to predict the FRP stirrup strain limit, which includes the effects of all influencing parameters.

Abstract Six large-scale high-strength concrete beams reinforced with basalt fiber reinforced polymer (BFRP) bars and stirrups and three corresponding beams without stirrups were constructed and tested for shear failure under four-point bending. The main parameters considered were the beam effective depth (300, 500, and 700 mm) and the stirrup spacing. The test results indicated that the size effect on shear failure could not be eliminated completely, as the initial shear crack, shear crack width, shear resistant components analysis, strain in the BFRP stirrups, and normalized shear strength were still related to the beam depth. The ACI 440-15 strain limit of 4000 µs could be relaxed with the condition that the serviceability requirement is satisfied. Furthermore, based on a collected database from the literature, an accurate and conservative equation was proposed to predict the FRP stirrup strain limit. The proposed equation includes the effects of all influencing parameters, which is more reasonable than the constant strain limit used by most design codes.