Introduction of active thermography and automatic defect segmentation in the thermographic inspection of specimens of ceramic tiling for building facades

Abstract

InfraRed Thermography (IRT) has proven to be a valuable diagnostic tool due to its real-time, remote, and nondestructive operation yielding accurate detection of the position of defect areas in building facade ceramic tiling. Ceramic tiles coating building facades are widely used throughout the world because of their technical and aesthetic characteristics. However, the detachment of ceramic tiles and the water infiltration in deep layers are still common problems. So, this paper proposes active infrared thermography as a thermographic acquisition mode, in contrast to the common use of passive thermography, and segmentation of defect areas and automation in the thermal image processing as added values never before proposed in the ceramic tiling thermographic inspection. For that, specimens of ceramic tiling for building facades were tested under different laboratory conditions, with inserted corks (simulating detachments), and by injecting water into holes drilled in the back surfaces (simulating water infiltration), as defects. Good results have been obtained in all the tests, both in dry and wet conditions in the specimens and for surfaces with homogeneous and heterogeneous surface properties, serving the introduction of this workflow for a first and fast inspection in ceramic tiling building facades. Future research will work with the fine-tuning phase of the methodology by applying it to real case studies.