Estimation of chloride ingress in uncracked and cracked concrete using measured surface concentrations
2002 (English)In: ACI Materials Journal, ISSN 0889-325X, Vol. 99, no 1, 27-36 p.Article in journal (Refereed) Published
The service life of repaired concrete bridge decks with chloride-initiated corrosion is estimated using real environmental loads. Major field data are presented from measurements of the surface concentration (SC) of chloride ions in concrete overlays in deicing environments. The diffusion coefficients (DC) of the overlay and the old concrete were estimated with different methods, used thereafter with the measured SC and the measured concrete covers (lower 5% percentile), to predict the service life with numerical methods. Numerical methods were used due to the varying SC, and because the concrete overlay and the old concrete bridge deck had different DC, and because the composite deck could hardly be treated as a semi-infinite body. The effect of chloride ions that accumulated at the soffit had to be considered for thin bridge decks. Both uncracked and cracked concrete were considered. The effect of the SC type on the service life was limited. Stopping the use of deicing agents was found to be beneficial for up to 30 to 40 years. Cracks increased the chloride ingress rate, and the effect increased considerably with high DC in the old concrete.
Place, publisher, year, edition, pages
2002. Vol. 99, no 1, 27-36 p.
concrete, deicer, overlay, diffusion
IdentifiersURN: urn:nbn:se:kth:diva-21313ISI: 000173838900004OAI: oai:DiVA.org:kth-21313DiVA: diva2:340011
QC 201005252010-08-102010-08-10Bibliographically approved