Concrete Corrosion in a Nitrogen Fertilizer Plant

The experience acquired by monitoring, over a period of 6 years, concrete corrosion by calcium-ammonium nitrate (KAN) in a nitrogen fertilizer plant is reviewed. The action of this kind of concrete corrosion typically passes unnoticed for a relatively long time. Usually it becomes apparent only by the secondary activity of climatic influences, or by the swelling of the reinforcement due to steel corrosion. It also has been established that concrete samples, already saturated with nitrate salts and thereby of a higher porosity, still retain for some time strength values matching concrete age.

The rate of KAN corrosion has been studied systematically on physical models in the laboratory. The process of concrete destruction is monitored by measuring the changes of important physical and mechanical concrete characteristics, in order to obtain data on the durability of concrete structures under the action of KAN.