Title:
Corrosion of Steel Bars in Concrete at Joints under
Tidal Environment
Author(s):
Tarek Uddin Mohammed and Hidenori Hamada
Publication:
Materials Journal
Volume:
100
Issue:
4
Appears on pages(s):
265-273
Keywords:
bar; corrosion; joint.
DOI:
10.14359/12663
Date:
7/1/2003
Abstract:
A detailed investigation on the corrosion of steel bars in concrete made with various joints was carried out. The specimens were exposed to a tidal pool for 25 years. Some specimens were also exposed for further deterioration in an accelerated chamber after 25 years. The items of investigation include bond strength, carbonation depth, chloride concentration, electrochemical and physical evaluation of corrosion, and deposits in the joints. Autogenous deposit (healing) in the joint plane prevents the corrosion of steel bars in concrete except at the joints with epoxy and latex paste. The presence of voids at the steel-concrete interface is the main reason for localized corrosion. Brushing off the laitance from the joint surface reduces the carbonation depth through the joint. The application of a mortar coat after brushing off the laitance shows the least carbonation depth compared to the latex paste and epoxy coats. The application of an epoxy coat after brushing off the laitance shows the strongest bond strength, but does not show the best performance against corrosion of steel bars in concrete at the joint.