Causes and analysis of steel structural failures - Assessment and Refurbishment of Steel Structures - page 47

• Optimizing the materials used, their combination and the anticorrosive protection
systems
• Prescribing and implementing periodic assessment inspections and regular professional
maintenance.
Due to corrosion, some parts of steel structures can be seriously damaged, and weakened.
In cases where cross-sections are weakened by corrosion, it is necessary to asses them by
static calculation. When reinforcing the parts damaged by corrosion, it is advisable not to
cover such parts (Figure 2.27) because new uncontrolled deposits of corrosive products
can occur there. The renovation of damaged parts can be an exception to that rule, but
special attention should be paid to such parts, and anticorrosive protection should be
provided carefully within reinforcing, e.g. by metallization, because in such a case it is
possible to exacerbate the damage by 'bridging' (Figure 2.28). Ultimate removal of a
damaged part depends on its constructional function, on the cost of removal, on the
danger of further corrosion, on indication of what cracks that could occur, on aesthetic
considerations.
Figure 2.27 Reinforcement of a girder
damaged by corrosion (a) correct, (b)
incorrect
Figure 2.28 Reinforcement of an area
weakened by corrosion