3D-modelling of corrosion crack opening

摘要

It is of great interest to investigate whether it is possible to estimate the reliability of a given reinforced concrete structure by observations of corrosion crack on the surface of the structure. In the paper recent progress in modelling of the deterioration of reinforced concrete structures is presented with special emphasis on the corrosion crack opening. Experiments and 2-dimensional FEM analysis seem to support that the relation between the reduction of the reinforcement diameter ΔD_(bar) and the corresponding increase in crack width Δw_(crack) in a given time interval Δt measured on the surface of the concrete specimen can be approximated by a linear function; Thoft-Christensen (2004). More recently the crack-corrosion index γ = Δw_(crack)/ΔD_(bar) is further studied with respect to its dependency on the diameter of the rebar and the concrete cover; Thoft-Christensen (2005). In the paper it is shown that the above-mentioned work can be extended to more realistic beam configurations when a 3-dimensional FEM modelling is used. The crack corrosion index may then be evaluated for a 3-dimensional beam by assuming a concentrated corrosion area of the reinforcement. In this way it is possible not only to investigate homogeneous corrosion, but also pit corrosion.