Evaluation of flexural capacity and ductility on high-strength concrete beams reinforced with frp rebar and steel fiber

Anotace: C60 class of concrete is produced with addition of hooked-end steel fibres at dosages of 0kg/m3, 39kg/m3, 78kg/m3, 117kg/m3, and its compressive strength and split tensile strength are measured. The flexural behaviour of high-strength concrete beams containing basalt fibre reinforced polymer (BFRP) rebars and steel fibres is investigated in the present study. An experimental program was set up and seven reinforced concrete beams have been tested, including one series with steel fibres content of 0%, 0.5%, 1.0%, and 1.5% in volume, and one series with ratio of BFRP rebars from 0.38%, 0.57% to 0.76%, 0.95% and tested under four-point flexural loading condition. The result revealed that with the addition of steel fibre, crucial properties of working performance, ductility, and bearing capacity is improved. By increasing BFRP rebar reinforcement ratio, desired ultimate strength is anticipated. Considering the deformability and energy dissipation, a synthesis ductility index for FRP and steel fibre reinforced beams was proposed; while a synthesis ductility index for FRP reinforced flexural structure was also advised. The model of the synthetic ductility index coefficient is verified by relevant experimental data, and was expected to give an insight into the problem of deformability and ductility for the FRP rebar (and steel fibre) reinforced flexural concrete member.