Maintenance planning for structures, for a long time, was a concept of keeping the structure in a good shape, hence, it can perform its expected duties. Yet, because of financial and physical limitations in the old definition, operational managers had to provide a more comprehensive description for maintenance of structures. Hence, a more professional definition for structural maintenance would be defined as: "Total technical activities in the component level connected to each other and economically balanced, in order to keep or get the structure in such a condition that it can accomplish its duties for a certain period of time with sufficient reliability, availability, serviceability, and durability” Toorn (1996).
According to the new definition, some targets such as maintenance and managerial targets could be identified. Maintenance targets try to assure an adequate level of reliability, availability, etc. and managerial targets mainly aim to minimise the associated maintenance costs. These targets will provide some tools and indicators which are so helpful to mathematically formulate the problems in structural maintenance planning. For instance, Annual reliability index can be used as an indicator if the purpose of maintenance planning is to reach a certain level of reliability or maximise it as affordable as possible.
Structural maintenance can include different kinds of actions which regarding to the type of action and their influence on the degradation process can be divided into four categories:
1- Preventive maintenance, 2- corrective maintenance, 3- observational maintenance, and 4- non-inspection maintenance.
Differences between these categories will be explained in next posts.
|Bridge maintenance: repainting (Photo: Fox Photos / Getty Images)|