Non-destructive Testing of Concrete and Masonry Structures Using Active Thermography - Influence of Surface and Bulk Properties

Non-destructive Testing of Concrete and Masonry Structures Using Active Thermography - Influence of Surface and Bulk Properties. The main objective of the investigations presented below have been the quantification of influences of thermal material properties as well as of different emissivities of the surface on the detectability of inhomogeneities in building structures using active thermography. Further on, methods for data processing have been tested to reduce these influences. Results are presented concerning the investigation of different concrete test specimens made of varying concrete compositions and surface coatings and modifications. Additionally, rising moisture was studied at a test specimen consisting of historic masonry. Data processing has been performed in time as well as in frequency domain.