Comparison of Corrosion of Damaged Fusion-bonded-epoxy-coated (FBEC) and Uncoated Steel Rebars

Author(s): Deepak K. Kamde and Radhakrishna G. Pillai
Paper category: Proceedings
Book title: Proceedings of the 71st RILEM Annual Week & ICACMS 2017,Chennai,India, 3rd -8th September 2017
Editor(s): Manu Santhanam
Ravindra Gettu
Radhakrishna G. Pillai
Sunitha K. Nayar
ISBN: 978-2-35158-196-4
ISBN: 978-2-35158-190-2 (Set)
e-ISBN: 978-2-35158-191-9:
Publisher: Published by RILEM Publications S.A.R.L.
Publication year: 2017
Pages: 286-293
Total Pages: 8
Language : English

Abstract: The fusion bonded epoxy coated (FBEC) steel rebars are supposed to be more corrosion
resistant than the uncoated steel rebars and prolong the corrosion initiation time. However, the
epoxy coating is prone to damage (scratches, cuts, etc.) due to rough handling during
transportation and at construction sites. Such damage to the coating can cause localized
corrosion (crevice, underfilm, etc.), even without the presence of chlorides. Therefore, FBEC
steel rebars have been banned in many developed countries. However, FBEC rebars are widely
used in India and some developing countries. This paper presents the corrosion performance of
damaged FBEC steel rebars. Macrocell corrosion specimens (Modified ASTM G 109) with (i)
damaged FBEC (FBEC – D) and uncoated steel rebars (thermo mechanically treated rebars)
were cast and tested for a period of about Six months. It was found that the electrochemical
measurement on steel rebars with highly dielectric epoxy coating and embedded in the mortar
was very challenging with ASTM G109 procedures. In other words, there were many cases
where ASTM G109 to detect corrosion initiation, but visual observations on autopsied
specimens indicated corrosion. Also, it was found that the FBEC rebars with damaged coating
can undergo premature corrosion even without the presence of chlorides (moisture - induced
crevice/underfilm corrosion). This may tremendously reduce the service life of RC structure.

Online publication : 2017
Publication type : full_text
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