Corrosion modelling in new concrete types

Purpose and goal

Mechanistic models as tools for investigation of corrosion on rebars in new concrete types in road environments have been evaluated and simulations have successfully been performed. Promising possibilities to use these models to examine geometrical effects in more than 1D (not only along the thickness of the concrete cover) were identified. Future work on exposure setups of concrete was considered necessary to find crucial modelling parameters and to be able to simulate new concrete types in road environments in a reliable way.

Expected results and effects

The use of mechanistic models enables detailed analysis of properties in reinforced concrete that dictate the initiation of corrosion. These properties are reactions, transport of ions, wetting, dissolution of gases and current distribution over space and time. However, some modelling parameters and validation examples are still missing. Therefore, the next step is to try to resolve these issues, mainly by setting up experiments in controlled environments. Such work will be quite demanding and require collaboration with more partners.

Planned approach and implementation

During the work a literature survey has been performed to get an overview of available models and experimental data. Thereafter, a mechanistic model in 1D was set up and some validation attempts against measurement data from the project partners were made. A simplified 2D model study followed this. Both model types were able to show valuable results in regards to corrosion when the concrete composition and geometry was changed. Several points for improvement of experimental and modelling work were suggested.