The use of active thermography to detect material inclusions in the walls

One of the non-destructive testing methods of building envelope of unknown structure is active thermography in reflective mode. This method was used to test a model of the concrete wall with the material inclusions with significantly different thermal properties. The study performed in climatic chambers consisted of heating the model wall with a 7.2 kW heat pulse, and then recording the thermograms during wall cooling, at regular intervals, using a thermal imaging camera. Based on the recorded temperature distribution on the thermograms the thermal properties and location of subsurface defects were concluded