Cracking behavior of basalt fibre reinforced polymer-reinforced concrete: An approach for the determination of crack spacing and crack width

The limitation of the crack width is of central importance for the design in the serviceability limit state. For FRP-reinforced concrete members, the crack width has to be limited for service condition in use and not due to corrosion protection. In this paper, an experimental program of pull-out tests and slender concrete cylinders with basalt fiber-reinforced polymer rebars under centric tension load is presented. The used basalt fiber-reinforced polymer rebars are sand coated and have in addition a helically wrapped thread for a decent profiling. Equations to calculate crack spacing and crack width of FRP-reinforced concrete is derived and calibrated with the obtained experimental results. Finally, the equations are verified with experimental data from other authors and a crack model is given for reinforced concrete members with FRP rebars with a helically wrapped and sand coated surface.