Analysis of the GPR signal for moisture detection: application to heritage buildings

Moisture is one of the main causes of degradation of heritage buildings. Early detection of zones affected by moisture is crucial information for preservation and maintenance of those structures. Ground-penetrating radar (GPR) is an effective survey method to assess damage in civil engineering and structures. Several methodologies involving this technique have been applied to determine the extension of damping in concrete, stone, and brick structures. This article summarizes the different signal analysis techniques generally used to detect moisture from GPR data. Four different case studies are included, covering different types of buildings. The case studies include the description of the problem, the results, the methodology (data acquisition, survey parameters, and processing), and the limits and advantages. Comparing the different studies, the limitations and advantages are associated with each type of problem and a final discussion describes other non-destructive testing techniques, numerical simulations and methodologies that could provide more reliable understanding when combined with GPR data.