Fracture Mechanics of Bond in Reinforced Concrete

A new approach is taken to predict numerically the bond-slip behavior of a reinforcing bar embedded in concrete. Attention is focused on radial, secondary cracking. This cracking is found not to follow the principles of linear elastic fracture mechanics, and therefore is modeled using a nonlinear, discrete crack, interface and finite element approach. A new method for finite element modeling of nonlinear fracture is presented. A "tension-softening element" is introduced for the purpose of modeling bond-slip in practical reinforced concrete engineering problems. Finally, as an example, a reinforced concrete tension diaphragm is analyzed.