Modelling of bond between galvanized steel rebars and concrete

In reinforced concrete structures, it is extremely difficult to ensure that steel bars will be not subject, either in a lower or higher extent, to the corrosion effect. The application of hot dip galvanized rebar is an economic and effective way of protecting reinforced concrete against corrosion. This protective technique has an influence, which should not be disregarded, on the performance of the rebar’s coating, its behaviour and, fundamentally, the bond between concrete and galvanized rebar. With the aim of studying the bond behaviour between galvanized steel rebar and concrete, an experimental program was carried out by means of direct pullout tests. To predict the full pullout response, an analytical cohesive interface model was developed to obtain the bond stressslip relationship. To account for the interfacial bond, a nonlinear bond stress-slip law was used. In the present work the numerical method and mathematical tools are detailed and its performance is assessed. Hence, the parameters that define the local bond stress slip relationship are obtained by a fitting procedure between the simulated pullout curve and the experimental one. Finally, the obtained local bond law relationship is compared to the one proposed by the CEB-FIP Model Code.