English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/46706
Share/Impact:
Statistics
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Potentiostatic determination of chloride threshold values for rebar depassivation: Experimental and statistical study

AuthorsIzquierdo, D.; Alonso, C.; Andrade, C.; Castellote, M.
KeywordsCorrosion of reinforcements
Chloride threshold
Electrochemical potential
Statistical approach
Log and normal distribution
Issue Date2004
PublisherElsevier
CitationElectrochimica Acta; Vol. 49; nºs 17-18; págs. 2731-2739 (2004)
AbstractThe presence of chlorides in concrete is the main cause of corrosion of reinforcements, responsible for most of the damages and cost losses attributed to the degradation of concrete structures. In spite of this, there are not enough data when defining chloride threshold determination. Most experimental work has been devoted to identify the variables involved in depassivation: type of cement, water/cement (w/c) ratio, pore humidity, type of steel, etc. Present situation considers a comparative value, in general, of 0.4% by weight of cement. In the present work, tests on mortar specimens were performed using several types of cements, covering a region of potentials from +250 to −650 mV (SCE) (+150 to −800 mV Mn/MnO2). Series of identical specimens made with different types of cement were used. A statistical treatment of the results of chloride threshold is made. Results indicate that two regions of potential are identified: (1) The region of potentials more positive to −200 mV (SCE). The mean values of chloride threshold for 95% probability of corrosion vary between 0.497 ± 0.126 and 0.569 ± 0.177 for free chlorides and 0.632 ± 0.112 and 0.771 ± 0.346 for total chlorides. The lowest limits of chlorides for corrosion initiation, from a normal distribution (characteristic values) are 0.283% for free chlorides and 0.316% for total chlorides (wt.% of cement). Differences in chloride threshold with the type of cement are identified after the statistical study of the experimental results. (2) For potentials more negative to −200 mV (SCE) the experimental results fit well with a log-normal function. A mean value for total chlorides of 1.53%, with a variation coefficient of 0.36 is found. A mean potential for protection of −500 mV (SCE) could be identified.
Publisher version (URL)http://www.sciencedirect.com/science/article/pii/S0013468604002403
URIhttp://hdl.handle.net/10261/46706
ISSN0013-4686
Appears in Collections:(CISDEM) Artículos
Files in This Item:
File Description SizeFormat 
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.