Abstract

Gypsum boards with glass mat reinforcement are used in light weight facade systems. These boards were recently brought to the Brazilian market. Therefore, there are few studies and little practical knowledge of their performance over time, mainly concerning to durability. The gypsum boards manufacturers set that these boards always need to be coated, however they can be exposed to natural conditions during the construction site period. A study is necessary to evaluate the feasibility of using these boards in Brazil, since the exposure conditions relating to humidity, temperature and solar radiation are different from Europe and North America. The aim of this paper is to show the approach used to evaluate the durability of the gypsum board with glass mat reinforcement, and also show the test results. In order to establish the durability approach, standards were adopted, as well as the functional performance concept. In addition, the tests considered that such boards would be used on the facade and should behave similarly to other boards used in facades in Brazil, such as fiber cement boards. Thus, mechanical tests were done in steady state, saturated and after aging in cycles of immersion, drying and heating. Other evaluations were made on gypsum boards applied on exposed walls. The results showed that even the board strength decreases after the accelerated aging cycles, the final value remains in an acceptable level. In addition, boards applied on exposed walls for 12 months have been presenting a good performance; meaning no cracks neither detachments, even though the follow-up still needs to be maintained longer.