There has been an increasing interest in the field of rehabilitation, mainly for repair and strengthening of reinforced concrete (RC) structures. One of the most effective techniques comprises externally bonded concrete composites, in which the efficacy of rehabilitation depends considerably on the integrity and durability of the bond established between the overlaying and the substrate concrete. This paper presents a detailed review of the critical durability issues associated with the structural bond for rehabilitation purposes, with a special focus on the performance of modern overlay materials such as ultra-high performance concrete (UHPC) and Engineered Cementitious Composites (ECC). A number of factors determining the durability of concrete-concrete bonded joints have been identified and grouped into two categories related to materials - joint characteristics and inservice conditions. For each of these factors, the main findings obtained in previous studies are summarized and discussed and the aspects that need further investigation are outlined.