Estudo das aplicações das variedades de um quartzo-sienito com hiperstênio, como rochas ornamentais, com auxílio da caracterização tecnológica e das análises de cor e imagem

• Ano de defesa: 2015
• Autor(a) principal: Bolonini, Thiago Motta [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Ornamental rocks; Rochas ornamentais; Colorimetria; Análise de imagem; Barra de São Francisco (ES)
• Link de acesso: http://hdl.handle.net/11449/136648; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/09-03-2016/000858296.pdf

The studied dimension stones commercially known as Butterfly Beige, Butterfly Gold, and Butterfly Green, correspond to quartz-syenite with hypersthene extracted at the Barra de São Francisco-ES, Brazil and are part of the suite G5 (granitic rocks with hypersthene) in the context of Araçuaí Orogen. The rocks show very similar compositional, textural and structural supported by the technological characterization, with results very close of the suggested to granitic rocks (except for the Amsler wear and modulus of rupture). In the chemical attack hydrochloric acid showed severe color changes to remove the resin, and the ferrous hydroxide and destroy the fractures and/or liberate the CO2 inclusions. In the accelerated aging, the color variation in Butterfly Green (ΔE after 100 cycles = 3.87) shows that wet sites and exposed to sunlight sites can, depending on the amount of SO2 in the atmosphere, enhance the occurrence of staining and loss of gloss. The permeability to the Butterfly Green (C = 0.0097) indicates that, in addition to the surface more easily changed, such changes can penetrate more in its structure. With respect to the decharacterization the Butterfly Gold had the lowest calculated time (3.08 years), followed by the Green Butterfly (3.91 years) and Beige Butterfly (16.03 years). It is noteworthy that the derived estimates do not prevent your outdoor applications, as cleaning procedures can be applied for conservation. In the thermal test, the values found for the correlation coefficients between the images of these rocks indicate that, already in the first 200° C, they were very affected receiving the moderate decharacterization classification associated with the cycles of contraction and expansion that disrupt the rock opening pores and increasing its capacity moisture absorption when in cooling process, causing the oxidation of minerals. The work as a whole, presents alternatives to understand and perform the ...