Cracks in Cement Lining and Coating
I was the Principal Investigator for the recently issued EPRI Technical Report “Guidelines for the Evaluation of Cracks in Cement Linings and Coatings”, Technical Report 3002000599, December 2013. I worked with EPRI’s Doug Munson to develop these guidelines to help nuclear plant utility engineers make fitness-for-service assessments of damage in cement-lined and cement-coated pipes.
Cement mortar is commonly used as internal (ID) or external (OD) corrosion protection barrier for steel pipes. When the cement coating is reinforced with steel wires it also provides strength to the pipe. Cement will tend to develop tight cracks while shrinking or during handling and installation. In the case of tight cracks, corrosion is mitigated by the alkalinity of the cement. If the cracks are too large, however, then the steel pipe may be subjected to corrosion.
The EPRI report provides practical guidance to differentiate between tight, cosmetic, cracks that will not lead to corrosion damage of the steel pipe, and those cracks that are a cause of concern.
Naturally Occurring Cracks in Cement Coating