Towards correlating natural and accelerated chloride-induced corrosion in cracked RC preliminary results

Author(s): M. Otieno, H. Beushausen & M.G. Alexander
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 194 – 196
Total Pages: 3
Language: English

Abstract: 
This paper presents preliminary results of an on-going study on chloride-induced corrosion in reinforced concrete. A total of 210 beam specimens (120 × 130 × 375 mm) were made using two w/b ratios (0.40 and 0.55), three binders (PC, PC/FA and PC/GGBS) and two concrete covers c (20 and 40 mm). Other experimental variables included crack width wcr (0, 0.4 and 0.7 mm) and exposure environments (field and laboratory). Accelerated corrosion by cyclic wetting and drying with 5% NaCl solution was used for the laboratory-based specimens while the field-based specimens were exposed to a natural tidal/splash marine zone. Corrosion rate (icorr), half-cell potential and concrete resistivity were measured every two weeks over a period of 30 weeks. Results obtained so far underscore the influence of wcr, c, resistivity and concrete quality on icorr, with the general trend showing icorr increasing with increasing wcr and decreasing c, resistivity and concrete quality. The results show that for a given set of experimental variables, both natural and accelerated cumulative mass loss follow a linear trend but with the latter having a higher slope. However, long-term results are required to confirm this linear trend with time. The ratios between the natural and accelerated icorr show high variability. This variability should be taken into account when correlating the two.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00