Critical chloride content in reinforced concrete

The critical chloride content (Ccrit) of reinforcement corrosion in concrete is of great importance for the condition assessment of existing structures and for the service life design of new structures in chloride exposure environments. Researchers recently reviewed the extensive body of literature on Ccrit published in Chinese since the 1960s. In agreement with earlier reviews considering European and North American literature, they find that Ccrit scatters widely and cannot be predicted on the basis of parameters such as w/b ratio, binder type, steel surface condition, etc.

Corrosion initiation in concrete should be treated differently

It appears that the stress state of the reinforcing steel may play a more important role than generally assumed. On the basis of this review, complementing earlier reviews, they conclude that the state-of-the-art on Ccrit has advanced negligibly over the last decades. The time is now to change the way corrosion initiation in concrete is scientifically addressed. Recommendations for further work are made.

The study is published in: Cement and Concrete Research Volume 117, March 2019, Pages 58-68.