| Abstract | Reinforced concrete is always exposed to environmental changes and thus can get deteriorated by different mechanisms which include: abrasion, erosion, cavitation, corrosion of steel, acid attack, sea water impregnation, carbonation, alkali aggregate reactions, freezing and thawing, salt crystallization, carbonation, and so on. Sometimes, reinforced concrete structures also suffer from minor damage to major damage during natural disasters such as: earthquakes, tsunamis, tornadoes, hurricanes, landslides, and so on. Therefore, as time progresses it is important to assess the level of degradation in concrete which allows us to timely maintain or retrofit the structure. Most of the damage detection methods follow similar pattern which is to properly analyze the response characteristics of a structure and discriminate the various states of the structural health. Environmental factors, such as temperature, may affect the vibration measurements in a way such that the presence of damage goes undetected. Moreover, moderate damage to the structure may not provide sufficient changes in natural frequencies and displacement mode shapes. Other modal parameters obtained from dynamic strain measurements such as modal strains and their curvature seem to have high-sensitivity towards local damage and prove to be promising indicators of local damage. In this thesis, a novel approach known as Frequency Factored Damage Index (FFDI) is adopted to identify the damaged structural component and determine the level of degradation these components have suffered in terms of reduction in the stiffness. |