Criteria for Identification of Ceramic Detachments in Building Facades with Infrared Thermography: Fid-Bau Portal

Criteria for Identification of Ceramic Detachments in Building Facades with Infrared Thermography

Bauer, Elton / Pavón, Elier / Pereira, Cláudio H. F. / Nascimento, Matheus L. M.

Abstract Infrared thermography is a nondestructive technique with great application potential to study the pathologies of buildings. The use of passive thermography to evaluate building facades subjected to sun incidence has allowed interesting advances in the identification of regions with initial detachments that are not visible on the facade surfaces. There are, however, several difficulties in the methodology, especially regarding the best moment to visualize the anomalies. These moments depend mainly on the heat flow in the facade, which is not constant. The objective of this study is to identify the best conditions to visualize the anomalies by performing field and laboratory studies to evaluate delta-T and contrast functions. To this end, a laboratory study was developed. It consisted of heating and cooling experimental base plates with manufactured internal defects, which were monitored by a sequence of thermograms obtained continuously. The field study consisted of evaluating an area of a building facade with detachment patches. The thermal evolution of the facade was monitored continuously by thermography for 10 h. The results indicate that delta-T cannot be used as the sole parameter to identify the anomalies. It is also highlighted that knowing the direction of heat flow is important since the contrast functions have shown that the anomalies are best visualized at the beginning of the heat flow, heating or cooling. It proved that the criteria obtained in the laboratory are applicable to field studies, especially if it is possible to analyze previously the heat flow on the facade.