This paper presents the results of three ground-penetrating radar case studies applied to indoor, bridge deck, and pier construction types in Turkey. In these studies, 270-MHz and 1600-MHz antennas were employed to determine the ability limits for construction materials and diagnostic problems associated with the materials. In addition, the importance of the selected survey direction was tested during measurement. Analysing the significance of the migration technique during the data processing stage was another important goal of these case studies. The first case study analyses the indoor applications (e.g., house, villa, and fabric) of ground-penetrating radar and aims to identify possible cracks, structural defects, and corrosion damage. The second case applies ground-penetrating radar to a bridge deck. The third case investigates pier construction by establishing the layout of the construction materials. Identifying possible defects, including structural problems within the pier structure, was another goal. These case studies provide interesting results in terms of physically characterizing the concrete structure and the locations of rebar and slab conditions; the work also reveals the moisture and corrosion effects inside the construction materials on indoor, bridge and pier applications of ground-penetrating radar.in civil engineering. Therefore, large volumes of oxidized zones inside the materials might cause significant damage through the effects of cracking and debonding. Consequently, the most critical problems and important deterioration effects may develop on bridges and pier decks. The corrosion of steel inside the reinforcement is mostly subjected to chloride ion exposure, moisture, and various iron oxides (FeO, Fe 2 O 3 , Fe 3 O 4 and others). In fact, this process, clearly defined by Neville and Brooks (1987), progresses rapidly in irons. This phase can result in debonding between steel and concrete due to water infiltration (Hubbard et al. 2003), delamination of the concrete cover material from the reinforcement, and cracking (Benedetto 2013). GPR is an important method in diagnosing progressive corrosion problems before damage. The visibility of GPR in non-destructive applications depends on the relevant electromagnetic contrast between the dielectric characteristics of uncorrupted and oxidized materials, which result from moisture among the steel and concrete materials (Halabe, Maser, and
