Project N.8
Title:
Chloride ingress and
corrosion of steel
in AAM concrete
Objectives
For the application of optimised AAMs in an aggressive marine or environment where de-icing salts are used, it is of paramount importance to prove their resistance to chloride ingress and the influence on corrosion of steel in concrete. The core aim of this ESR project is to develop understanding of chloride ingress and resulting chloride-induced corrosion of steel in AAMs and propose a methodology of their mitigation.
To achieve this aim, the following objectives are defined:
| 1) | Perform experimental campaign focusing on testing the corrosion behaviour of AAMs on three levels: 1) on pore solution level, where steel is directly tested in extracted or prepared pore solution from AAM, 2) on laboratory sample level, where samples with embedded steel are exposed to natural and accelerated corrosion induced by chlorides, 3) on real scale level, where real scale samples are exposed to real environments in field exposure sites, |
| 2) | Validate the application of testing methods developed for classical OPC systems for testing chloride ingress into AAMs, as well as electrochemical testing methods for testing corrosion activity, |
| 3) | Develop phenomenological models of behavior of steel in AAM concrete during initiation and propagation of chloride-induced corrosion, with special highlight on differences in the degradation mechanism compared to classical OPC systems (binding of chlorides, propagation of corrosion products through pore system, crack formation, etc). In this part findings from ESR 2 and 3 will be used as input, while the findings of ESR8 will be used as input in ESR 9 and 12. |
Expected Results
| 1) | Understanding of chloride ingress in AAMs systems, |
| 2) | validated experimental techniques for testing chloride ingress in AAM concrete, |
| 3) | in-depth explanation of chloride-induced corrosion of steel in AAM concrete, including initiation and propagation phase, |
| 4) | definition of prevailing parameters in AAM systems for ensuring prolonged durability and resistance in environment where chloride-induced corrosion is the prevailing degradation mechanism, |
| 5) | experimental data for service life modelling of AAM concrete, |
| 6) | design recommendations for the application of AAM concrete in marine and environment where de-icing salts are used. |