Critical thickness of rust layer at inner and out surface cracking of concrete cover in reinforced concrete structures

This study investigated three electrochemically corroded reinforced concrete specimens. The thickness of rust layer at inner and outer surface cracking of concrete cover was measured by digital microscopy. The rust layers at steel/concrete interface and the rust distributed in corrosion-induced cracks were observed by SEM. A uniform millscale layer was found on the surface of the corroded steel bar. Observation also reveals that rust does not fill the corrosion-induced cracks. The measured thickness of the rust layer at inner and outer surface cracking of concrete cover is in agreement with the predicted results from the proposed mode. (C) 2012 Elsevier Ltd. All rights reserved.