Termografia como instrumento de identificação de manifestações patológicas em igrejas históricas

Abstract

If the occurrence of pathological manifestations is elevated at contemporary constructions, at the old ones the probability is bigger. Secular buildings become susceptible to deterioration over time, whether due to use, design decisions not appropriate to the construction techniques used, lack of maintenance or damage due to inadequate interventions. Structures affected by some type of pathological problem should not be condemned without prior evaluation, since rehabilitation may be feasible. The Metropolitan Region of Belo Horizonte (RMBH) has a vast set of churches built between the 17th, 18th and 19th centuries under current guardianship of patrimonial preservation organs. Nevertheless, although some of these buildings are protected, they are in critical condition of conservation. In this context, this article proposes the verification of the efficiency of a preliminary alternative method for the evaluation of the situation of these buildings, with a view to advancing the current technological framework of analysis. A non-destructive technique called thermography was used to identify possible pathological manifestations, which is based on the generation of thermal graphs through the capture of heat irradiated by preheated surfaces. The differentiation of temperatures in homogeneous planes can indicate irregularities such as infiltrations, cracks etc. The studies were conducted on the external facades of five churches of the Metropolitan Area of Belo Horizonte, due to exposure to direct sunlight. The records allowed the identification of possible causes of damages, as well as the prescription of critical points in the various systems of the buildings, which serve as an investigative contribution for further analysis. In addition, the common diagnoses of the churches were inventoried, given the technological similarities adopted in their conception. The thermography was an adequate technique, since it did not require any type of physical intervention in the buildings, being indicated for similar studies.