Corrosion crack widths are often used by structural engineers in the field to predict level of steel corrosion
as well as residual load-bearing capacities of corroding RC structures. This paper presents further
work on this matter but with focus on corrosion crack patterns and how they affect rate of crack widening.
It is based on results from a research where 17 quasi-full-scale (153 254 3000 mm) RC beams
were corroded under various levels of sustained loads. The rate of widening of corrosion crack widths
was found to be very much dependent on crack patterns. Deformation of cover concrete under each crack
pattern was discussed. It was found that at maximum crack widths below 0.6 mm, the majority of beams
exhibited nearly similar crack patterns as well as rate of widening of corrosion cracks. A mass loss of steel
of 1% corresponded to a maximum crack width between 0.14 and 0.22 mm. At large crack widths
(>0.6 mm), various beams exhibited very different rates of crack widening. It was shown that at crack
widths above 0.6 mm, to be conservative an increase in mass loss of steel of 1% corresponded to corrosion
crack widening of 0.02 mm.