PSI - Issue 73

Petr Mynarcik et al. / Procedia Structural Integrity 73 (2025) 112–118 Petr Mynarcik, Miroslav Vacek, David Mikolasek, Vladislav Bures/ Structural Integrity Procedia 00 (2025) 000–000

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2. Corrosion simulation and precision 3D profilometric scanning 2.1. Salt spray test chamber – corrosion testing samples

For better understanding of the patented process, wires from the truss were removed from the truss. The selected undamaged wires are documented, and the weight of each 400 mm long sample was noted. This preparation step is made because it is necessary to know the corrosion loss of each sample after exposure. Corrosion damage is caused by a corrosion salt spray chamber with a setting according to ISO 9227 [7]. 30 saples are divided into 3 sets by 10 samples. The first set was exposed in the corrosion chamber for 60 days, the second set for 100 days, and the third set for 140 days. The temperature in the corrosion chamber was set at +35 ° C and a solution of NaCl 5 % was used. These sets of samples are intended to simulate real corrosion attack of prestressing wires in a real structure. 2.2. 3D profilometric scanning – corrosion testing samples In similar studies, manual measurement with a micrometer [5] or a combination of a micrometer and a 3D scan with a lower resolution [6] than in our research was used to assess the depth of corrosion. These methods seem to us to be surmountable by using a highly accurate profilometer. For the best possible precision is made 3D profilometric scanning using Keyence VR-6200. This technology allows to scan surface with precision of 0,1 µm. For the samples, a precision of approximately 50 µm is used. This precision is achieved because of better knowledge of the local stresses in the destructive test. The part of scanning surface of the wires after the 60 days, 100 days and 140 days exposure are depicted on Figure 4, 5 and 6.

Fig. 4. Precision 3D profilometric scan - sample 60 days in corrosion atmosphere exposition