Relating visual inspection to structural effects of natural corrosion in reinforced concrete structures

Research Project, 2014 – 2017

Corrosion of steel reinforcement is the most common cause of deterioration of reinforced concrete; and the deterioration is expected to become even worse due to climate change. In addition, the demand for load-carrying capacity often increases over time. Thus, there is a growing need for reliable methods of assessing the load-carrying capacity and remaining service life of existing structures. Today, there are very weak links between inspections and assessment which will be addressed in this project. Test specimens with naturally corroded reinforcement with detailed documentation concerning amount of spalling, crack pattern, and crack widths of the surrounding concrete will be used. The reinforcement bars, with varying degrees of corrosion, will be tested in tension, providing information about corrosion level and ductility. The documented cracking will be linked to the corrosion level; detailed modelling will be used to form an understanding of the phenomena, and based on that, simplified methods will be developed. Furthermore, the corrosion level will be linked to the ductility, again using advanced modelling to describe e.g. corrosion pits, to form the base for simplified models that can be used in practice. The results of the project will contribute to significant economic and environmental savings as, with the gained knowledge, we can repair and replace existing structures only when it is necessary.