Abstract:The building envelope is subject to a range of natural stresses, including temperature differences, precipitation, wind, vibration, and other environmental factors. These stresses, in combination with the continuous action of ageing, can lead to the formation of hollow drums, leakage, and other defects. These defects can ultimately result in the collapse of the building's wall brickwork, potentially endangering personal safety and property. In this paper, an innovative approach is proposed for the rapid detection of defects on the external wall of a building. The proposed method utilizes infrared thermal imaging technology to identify temperature anomalies in hollow drum defects. The study then proceeded to analyze the temperature distribution characteristics of different regions on the infrared thermal image of the building exterior wall under sunlight irradiation, as well as the boundary intrusion phenomenon in the temperature uniform region of the beam and column structure of the exterior wall and the infill wall in the presence of defects. The boundary pixel position of each temperature region was then extracted using the watershed algorithm, and a boundary pixel stacking folding map was established to identify the abnormal region. The efficacy of the proposed method in identifying and locating the intrusion and anomalous pixel points in the thermal image is demonstrated by a MATLAB-based image processing simulation. The paper also presents a rapid inspection and assessment scheme for the quality of urban high-rise building facades, which is designed using the example of Leixinjiayuan in Changsha Tianxin District.
