Influence of concrete cracks on reinforcement corrosion

Responsible: Carolina Boschmann Käthler

Collaborations: Norwegian Public Roads Administration

Concrete Cracks

Background

Reinforced concrete is in practice often cracked due to several reasons. Engineers undertake many efforts for crack control (e.g. to limit crack widths) and crack repair, but it is still unknown to what extent cracks influence corrosion of the embedded reinforcing steel. Since the 1970s, the existence of a critical crack width is controversially discussed and has been subject to many research studies. Whereas the influence on corrosion initiation is evident from the literature, the results for corrosion propagation are unclear.

State-of-the-art report published 2017:

More background information can be found in a state-of-the-art report that can be downloaded external page here

Aims and objectives

The aim of this project is to investigate the long-term influence of cracks on chloride-induced corrosion propagation (corrosion rate).

Methodology

Cracked reinforced concrete beams are exposed in a simulated outdoor environment (chloride-bearing splash water exposure) and a number of electrochemical parameters are monitored. Different parameters, which may influence the local corrosion mechanism at the cracks are investigated, namely a hydrophobic surface treatment, cover depth, w/c-ratio as well as different crack widths and the existence of multiple cracking.

Crack Methodology