content_image/418344.jpg content_image/418352.jpg content_image/418343.jpg
<img src='content_image/418344.jpg'>

cubes were initially subjected to corrosion and subse- quently pulled out. 

<img src='content_image/418352.jpg'>

The concrete used in the experiments is charac- terised by a Young’s modulus of E$_{c}$ = 22 . 6 GPa, Poisson’s ratio of ν$_{c}$ = 0 . 17 , a tensile strength of f$_{t}$ = 2 . 7 MPa and a compressive strength of f$_{c}$ = 24 . 7 MPa. The Young’s modulus of the reinforce- ment is E$_{s}$ = 183 GPa. In the present study ,the re- sponse of concrete, reinforcement and bond between concrete and reinforcement is modelled by the lattice 

<img src='content_image/418343.jpg'>

approach described earlier. The lattice for the analy- ses is shown in Figure 6. For the reinforcement and the interface between reinforcement and corrosion, the mesh is structured. For the concrete the lattice is random. 

Three analyses were performed. In the first anal- ysis the reinforcement was pulled out without initial corrosion. In the other two analyses, corrosion per- centages of ρ$_{c}$ = 3 . 2 and 16 . 8 % were considered before the pullout. Assuming uniform corrosion, the corrosion percentages were transformed according to Equation 8 to corrosion penetrations of x$_{c}$ = 105 and 571 µ m. With an expansion ratio of λ$_{c}$ = 1 . 4 , this gives, according to Equation 7, free corrosion product expansions of u$_{c}$ = 41 . 6 and 214 . 8 µ m, respectively. With an interface element thickness of 1 mm, this gives eigenstrains of ε$_{c}$ = 0 . 0416 and 0 . 2148 . In all three analyses, the load F was controlled by the end slip in the form of relative horizontal displacements of nodes A and B as shown in Figure 5a. The results of the analyses are compared to the experimental re- sults in the form of average bond stress-slip curves shown in Figure 7. Here, the average bond stress was determined as τ = F/ ( π GLYPH<diameter> ℓ ) , where ℓ = 6 GLYPH<diameter> is the em- bedded length. 

The pre-peak regime of the load-split curves ob- tained in the analyses is in very good agreement with the experiments. However, the post-peak responses obtained in the analyses deviate considerably from those reported in the literature. In particular, the anal- ysis of the corrosion free case exhibits a more brit- tle response than reported in the experiments. On the other hand, the load-slip curves with initial corrosion exhibit a more ductile response than reported in the experiments. This is surprising, since it is expected that cracking in the concrete cover should reduce the pressure at the interface and, thus, also the tangential stresses. Consequently, a more consistent pattern of 

