Evaluating the damage degree of cracking in facades using infrared thermography

Abstract

The study of facade cracking is of great importance in the investigation of pathologies and degradation, as well as in the rehabilitation processes of buildings. Cracking is one of the major defects in facades; so assessing damage severity is necessary to define the best maintenance and rehabilitation strategies. The infrared thermography has been increasingly used as an inspection technique to identify and map facade defects and their severity. The use of hygrothermal simulation to understand the dynamics of the heat flux allows to observe important references that can help in the interpretation of the thermogram under different heating or cooling conditions. This study investigates the use of the quantitative passive thermography to measure the damage degree of cracks in a building facade. The crack depth was evaluated by the Delta-T values investigated in the three cracked regions. For the width, the variation of the studied temperature in a line transversal to the crack was used. The analysis was performed at a distance of 33 m from the facade. The conclusions corroborated the importance of the hygrothermal simulation as a pre-thermography technique, which made it possible to limit the period of investigation focusing on the phenomena of interest. It is also observed that it is possible to obtain quantitative values of the degree of damage by thermographic investigation. The measurement of the damage degree, in turn, brings important contribution to the application of the inspection technique.