Click here to see the NCR no. 55 2016/2 (pdf document)
Esben Østergaard Hansen, Master student (Civ. Eng), B.Sc.
Martin Riis Iskau, Master student (Civ. Eng), B.Sc. Eng.
Marianne Tange Hasholt Associate professor, M.Sc., Ph.D.
Technical University of Denmark Department of Civil Engineering
“Chloride Ingress in Concrete with Different Age at Time of First Chloride Exposure”
Concrete structures cast in spring have longer time to hydrate and are therefore denser and more resistant to chloride ingress when first subjected to deicing salts in winter than structures cast in autumn. Consequently, it is expected that a spring casting will have a longer service life.
This hypothesis is investigated in the present study by testing drilled cores from concrete cast in 2012 and 2013 on the Svendborgsund Bridge. The cores are subject to petrographic examination and mapping of chloride profiles. Moreover, chloride migration coefficients have been measured. The study shows that the effect of the extra time of hydration obtained when casting in spring increases the expected service life of the concrete structure significantly.
Key words: Chloride ingress, age-dependent chloride diffusion coefficient, field exposure, service life.