Ueli Angst
Bio
Ueli Angst obtained his degrees in civil engineering from ETH Zurich in Switzerland (MSc, 2005) and from the Norwegian University of Science and Technology, NTNU (PhD, 2011). He gathered 7 years, some of it part-time, of practical experience as corrosion consultant. In 2017, inspired by having seen the relevant questions in engineering practice, Ueli Angst established his research group “Durability of Engineering Materials” at ETH Zurich (www.ifb.ethz.ch/durability). The mission is to develop new and fundamental understanding about corrosion mechanisms to enable better assessments and predictions of the performance of engineered materials and structures across disciplines. His research group uses experimental and computational methods covering corrosion science, electrochemistry, materials science, porous media, reactive mass transport, and civil engineering. Ueli Angst received several awards for his work, including the Robert L’Hermite medal awarded by RILEM in 2017, and he is active in various international committees. His research related to inspection and monitoring led to a SpinOff (www.duramon.ch), founded in 2021.
KeyNote
Steel corrosion in concrete – Achilles‘ heel for sustainable concrete?
Abstract
Climate change is one of the main challenges faced by humanity and it is well-known that the cement, concrete and construction industries have the potential to make significant contributions to mitigate global warming. The reduction of greenhouse gas emissions from cement and concrete production inevitably leads to decreased alkalinity of the pore solution within concrete. This is generally perceived as a durability problem, because the prevailing doctrine – deeply rooted in text books, lectures, codes and design rules, standardized test methods, durability indicators, etc. – assumes that reduced alkalinity (e. g. carbonation) leads to corrosion of the embedded reinforcing steel. It is exactly this paradigm that presents a barrier preventing the potential of low-emission cements and concretes from being fully exploited. Practical experience, however, shows that the loss of alkalinity does not necessarily lead to significant steel corrosion, because other factors play a role as well. This knowledge presents an opportunity for a new paradigm that allows controlling corrosion while tolerating reduced alkalinity. However, this change can hardly be successfully achieved on the basis of empirical experience. Instead, science-based models are needed to predict the performance of new concretes in their actual service conditions. This contribution showcases advances made in the fundamental understanding of reinforcing steel corrosion as well as coupled processes occurring in the cementitious matrix at the steel-concrete interface. Opportunities for integrating these findings in corrosion modeling are discussed.