This thesis aims to address the durability concerns of Queensland’s concrete bridges. Focus is given to those bridges under the authority of the Department of Main Roads in the Gold Coast region. These represent the most heavily loaded bridges in the district and are located in the most aggressive environment. This dissertation begins with an explanation of the generated database and all of the information contained therein. The significance of each column to the durability performance of the concrete bridge network is highlighted.
Chloride attack, alkali-silica reaction and carbonation are the main deterioration mechanisms affecting the integrity of concrete structures. A general overview of each of these processes is provided as well as a description of the various identification techniques. The extent of these deterioration mechanisms on the bridge network is then highlighted. Any trends relating to the exposure classification, distress mechanisms and bridge components are also identified. Following this, existing repair techniques for the restoration of concrete bridges are described. Focus is given to their application, effectiveness and cost. Finally, two case studies are presented on the Nerang River Bridge and the Tallebudgera Creek Bridges.
Areas of future research have also been identified.
The lack of easily accessible information has prevented the thorough investigation of the durability performance of concrete bridges in Queensland. From this research, it was concluded that 37% of bridges in the Gold Coast are defective and in need of repair. Furthermore, engineers need to have a sound knowledge of the various distress mechanisms and the ways in which to limit their occurrence on local concrete structures. During the initial design stages, particular focus needs to be given to the environmental conditions in which a structure is located. In addition, strict quality control needs to be ensured during construction to guarantee that these design requirements are achieved.