A comprehensive assessment of the service life of reinforced concrete should include three aspects: modelleing of chloride ingress, estimation of critical condition, and measurement of corrosion rate once the active corrosion is onset. In the past decades, Swedish researchers have made remarkable progresses in modelling of chloride ingress ( devloped a standard rapid method NT BUILD 492 and an applicable scientific model ClinConc) and measurement of corrosion rate ( developed a rapid method for mapping corrosion in the field).
However, the progess in estimation of critical conditions seems not satisfactory due to the fact that the chloride-induced corrosion is a pitting corrosion, which strongly dependent on the micro-structure and the micro-cliamte of the conrete-steel interface.
This project intends to improve the knowledge and understanding of critical conditions for depassivation of steel in conrete, so as to be able to complete the knowledge-based tool for lifetime design of concrete structures exposed to severe environment.
In the project the conrete-steel interface under various critical conditions will be investigated by means of "standard" macro-scale and meso-/micro-scale analysis. Thus the proper relationships between average threshold values and key material properties and exposures environments could be established.
The project is carried out at the Division of Building Technology, research group Building Materials.
Nelson Dias Ferreira Da Silva