Combined approach of GPR and thermographic data through FDTD simulation to analyze masonry bridges: The evaluation of construction materials in a restored masonry arch bridge

Ground penetrating radar is a well-established technique on civil engineering applications. The study case of a medieval masonry arch bridge that has suffered different building phases throughout history is presented. Given that the characterization of construction materials is crucial to the stability and durability of the structure, the identification of the most critical portions represents an important task. However, when evaluating complex and heterogeneous structures, the method still needs improvements and new developments in the interpretation of the reflection profiles produced. Thus, this work presents new numerical modelling approaches to improve the interpretation process, which combines data produced from different non-destructive methods. Photogrammetry was used to create large-scale models, and the characterization of the dielectric properties of media was performed from field GPR and infrared thermographic data.