ANÁLISE DE ENSAIO DE CHOQUE TÉRMICO EM ALVENARIA DE GESSO COM TERMOGRAFIA INFRAVERMELHA

Abstract

The constructive modality of gypsum attracted the construction industry to the use of gypsum plaster blocks both in internal and external walls, increasingly common in the Northeast of Brazil. Although their use is regulated by the gypsum block standards for vertical seal NBR 16494 and NBR 16495, the lack of technical material makes it difficult for users to approve. Therefore, the performance standard NBR 15575-4 aims to establish criteria that ensure the proper functioning of the systems, such as durability with the thermal shock test, which is the purpose of this study. This research was divided in two parts: the characterization of the gypsum blocks according to the criteria of NBR 16494 through the test methods of NBR 16495 and the behavior analysis of a masonry, made in dimensions 1.60m x 2.35m with plaster blocks during the first cycle of the thermal shock test. The cycle consists of one hour of exposure to a temperature of 80ºC and a cooling with water jets until the temperature stabilization. To perform this analysis infrared thermography was used to record thermograms at the beginning, middle and end of the heating, as well as in the cooling according to the appearance of pathological manifestations. Thus, although without degradation in the masonry, it was possible to verify the appearance of infiltrations and monitor their progress, to visualize the heat transfer and the influence of humidity during the heating and cooling of the masonry.