Oxide Jacking of Reinforced Concrete

Application ID: 92611

Oxide jacking is the process by which reinforced concrete cracks, due to the corrosion of the reinforcing rebar rods. The corrosion process causes growth of an oxide layer on the rebar, which in turn causes internal stresses in the concrete. If the corrosion process is allowed to continue unchecked, the concrete will eventually crack, compromising the structure.

In the present model, a 2D model for oxide jacking is presented. The corrosion process is driven by oxygen reduction, and is modeled using tertiary current distribution. Oxygen diffuses from one side of the concrete block, which is assumed to have a water pore saturation of 60%. The rebar and concrete surroundings are modeled as linear elastic materials, with initial strains in each time-step based on the thickness of the oxide layer. As a simplification, only one piece of rebar is included.

Under these conditions, a crack from the rebar to the outer surface of the concrete has formed after 750 days.

This model example illustrates applications of this type that would nominally be built using the following products: