CORNET-CRUFI modelling of transient heat and moisture behaviour and prediction of reinforcement corrosion in concrete and recycled concrete

Project content and origin of the idea: This international project, in which the Fraunhofer Institute for Building Physics, the University of Applied Sciences Campus Vienna and the Universidade do Estado de Minas Gerais are involved, is investigating the durability of concrete with and without chloride-containing recycled aggregate. The aim is to develop transient prediction models for reinforcement corrosion under various conditions such as temperature, humidity and corrosiveness of the pore water.

Concrete protects the reinforcing steel from corrosion through its alkalinity. This protection is lost during carbonation, which occurs more quickly in dry concrete than in wet concrete. Corrosion of the steel occurs mainly in wet concrete and although models for carbonation exist, there is a lack of such models for transient corrosion prediction, especially considering variable temperature and humidity. A refined material model that takes into account the temporal moisture distribution in the concrete is therefore necessary.

The research is intended to show that recycled materials containing chloride can be used under certain conditions without harmful corrosion. It will also contribute to the development of sustainable concrete mixes that require less cement clinker and bind CO2 more efficiently.