As the old railway building in Katowice was planned to be restored and expanded, the complex tests on technical conditions of the main structural elements, including the original hub columns, were performed. The tests included assessment of mechanical properties of concrete and reinforcing steel, and advanced corrosion measurements. I was a member of a team conducing the corrosion tests. Their results surprised the employer.
Problem outline, purpose and scope of tests
As the old railway building in Katowice was planned to be restored and expanded, a design concept was prepared which included the maintenance of hub columns that were unique in Europe. In accordance with laws and regulations, the existing elements of the previous structure have to be assessed regarding their natural wear before including them in the designed structure. The Department of Building Structures at the Silesian University of Technology decided to perform that task which was divided into two groups. The first group included strength tests consisted in non-destructive location of rebars in the structure, and evaluating concrete homogeneity by the sclerometric method. The second group included corrosion tests on concrete and steel. As part of such tests, stationary potential of the reinforcement was measured and concrete cover resistivity was tested. Also cylindrical concrete cores were drilled from the structure. They were used in concrete compressive tests and polarization tests of corrosion rate in concrete.
Summary and conclusions
Results from the corrosion tests were surprising for the employer who expected the severe corrosion degradation of reinforced concrete in the structure operating for over 40 years. The technical opinion only indicated the possible corrosion risk of concrete reinforcement in case of high moisture content in the structure. Only measures reducing the possible dampening of the structure were recommended. As the test results complicated the employer's plans of restoring the building and initiated the public debate on that matter, the authors of the technical opinion decided to discuss the obtained in results in several articles in Polish industry magazines.