State of conservation of a modernist curtain wall: statistical studies of factors that affect the natural aging pattern

Abstract External vertical sealing systems constituted of steel and glass curtain walls become vulnerable after years of use, and their functional and technological obsolescence increases the need for retrofitting. In the 1960s and 1970s, carbon steel curtain walls were widely used in modernist buildings, which justifies efforts to understand how their degradation occurs over the years. With the aim of outlining a method to investigate the state of conservation in order to understand the natural aging pattern of this type of system, this research study statistically evaluated the behaviour of the curtain wall of a 1960s building located on the Esplanade of the Ministries, in the Brazilian capital, Brasilia. To this end, a building inspection was carried out and the data fed the statistical analysis, where multiple comparisons between variables were used to understand how the façade aged and to discuss cause-effect relationships. The ground floor presented the worst state of conservation. The fixed frame typology was the most preserved. When the horizontal sections were evaluated, the results showed that the facade aged in a similar way, except for the corrosion state at the joining with the north facade, which presented the worst results.