Inspection and evaluation are the beginning of any rehabilitation and renovation works. Inspection and evaluation of infrastructure condition are typically conducted by a multidisciplinary team that includes architectural, structural, mechanical, and electrical engineers. During the inspection and evaluation process, the participants verify whether the infrastructure is generally built up in conformance with the original construction documents, sketch out some of the observed structural elements and note their condition. Inspection of existing structures is characterized as the process by which any deterioration in the structure is observed and recorded while evaluation normally refers to all works to determine and assess the condition of the structure based on the results obtained during inspection. It is intended to evaluate the general condition of the structure and identify any areas of deficiency. The followed repair work is largely based on the conclusions of the previous inspection and evaluation. According to the FIP Guide to Good Practice of Inspection and Maintenance of Reinforced and Pre-stressed Concrete Structures (Bilger et al. 1986), the main reasons for inspection and maintenance of structures are:
1 to control the functional requirements and provide assurance that the structure is safe and fit for its designated use;
2 to identify actual and potential sources of trouble and misuse at the earliest possible stage, and to prevent serious deterioration and failure, consequently increasing the service life;
3 to monitor the influence of the environment since there is a relation between the aggressiveness of the environment and the durability of concrete structures; the increasing content of aggressive agents in the atmosphere, acid rain and the use of de-icing salts considerably diminish the life expectancy of concrete structures;
4 to provide feedback of information for designers, constructors and owners on the factors governing maintenance problems, to which necessary attention should be best paid during the design and construction stages;
5 to provide information on which decisions concerning preventive
measures and work can be made; it is cheaper to repair minor damage at an early stage than to replace major components or the total structure in the event of failure.