Crack shape and rust distribution in corrosion-induced cracking concrete

This study investigated a reinforced concrete specimen that had deteriorated in an artificial environment for 2 years. The crack width and the rust distribution were observed by digital microscopy. The variation of the total circumferential crack width along the radial direction is presented using a linear function. Observation reveals that rust does not penetrate into the corrosion-induced cracks before concrete surface cracking. After concrete surface cracking, rust fills the cracks, lining the edges of the cracks due to the circulation of the outer solution. A schematic diagram is proposed to describe crack propagation and rust development.

► The total circumferential crack width is linearly proportional to the radius.
► Rust does not penetrate into the cracks before concrete surface cracking.
► Rust lines the edges of the crack after concrete surface cracking.
► A schematic diagram is proposed to describe crack propagation and rust development.