The development of bending cracks in fibre reinforced concrete (FRC) beams with main rein- forcement bars is modelled applying the fictitious crack model. A beam subject to bending moment and nor- mal force is modelled. Closed form solutions are given…
The development of bending cracks in fibre reinforced concrete (FRC) beams with main rein- forcement bars is modelled applying the fictitious crack model. A beam subject to bending moment and nor- mal force is modelled. Closed form solutions are given for the bending moment and crack opening, spacing and length; all functions of the cross-sectional rotation and the normal force. The model may be conceived as an adaptive hinge element, only considering the part of the beam, which is affected by the developing crack; this part defined by the length of reinforcement de-bonding. Constant friction is assumed between the de- bonded bar and the FRC. The stress-crack opening relationship, modelling the tensile behaviour of the FRC, is taken as a constant level instantly dropping from the uni-axial tensile strength, and the effect of fibres is studied by varying this post-peak stress level. Finally, the model is applied for the determination of beam de- flections.