This paper deals with the effect of steel cross-section and bond strength reduction on the mechanical behaviour of corroded RC-beams. In the case of corroded reinforced concrete members, those effects are always coupled and a previous study (part one) has shown that it is not realistic to forecast the behaviour of corroded beams merely in terms of steel cross-section reduction. The object of the study is thus to understand the separated and coupled effects of the reduction in bond strength and steel cross-section. These investigations are carried out in order to be able to model the behaviour of corroded structural members and to predict how and when repairing is necessary. Different experimental simulations of corrosion were made. The results show the significant impact of coupling between reduction of bond strength and steel cross-section.