Climate change adaptation for corrosion control of concrete infrastructure

摘要

The durability of concrete is determined largely by its deterioration over time which is affected by the environment. Climate change may alter this environment, especially in the longer term, causing an acceleration of reinforcement corrosion that will affect the safety and serviceability of concrete infrastructure in Australia, US, Europe, China and elsewhere. This paper reviews advanced simulation procedures to predict increases in damage (corrosion) risks under a changing climate in Australia in terms of changes in probability of reinforcement corrosion initiation and corrosion induced damage due to (i) increase in the concentration of CO_2 in the atmosphere, and changes to (ii) temperature and (iii) humidity. These time and spatial variables will affect the penetration of aggressive agents CO_2 and chlorides into concrete, and the corrosion rate once corrosion initiation occurs. The effectiveness of adaptation measures for new and existing buildings, bridges, and other concrete infrastructure is then assessed. Carbonation-induced damage risks may increase by more than 16% which means that one in six structures will experience additional and costly corrosion damage by 2100. We show that the impact of climate change on infrastructure deterioration cannot be ignored, but can be addressed by changes to design procedures including increases in cover thickness, improved quality of concrete, and coatings and barriers. For example, an increase in design cover of 10 mm and 5 mm for structures where carbonation or chlorides govern durability, respectively, will ameliorate the effects of a changing climate.