PSI - Issue 22

182 J. Gonçalves et al. / Procedia Structural Integrity 22 (2019) 181–188 J. Gonçalves, C. Oliveira, C. Reis, A. Soares, P Silva / Fir t Internati nal Symposi m on Risk and Safety of Complex Structures and Components (2019), Porto, Portugal

Ornamental stone has been used since ancient times, by humans, for construction. In recent years, the use of stones, such as granite, for the construction of tiles, facades or roads, has expanded greatly, both in residential buildings and major architectural works (Vásquez, 2010). According to Sanmartín, ( P. Sanmartín; B. Silva; and B. Prieto, 2011), the popularity of granite in the building, construction, monument, and tombstone industries is attributable not only to its resistance to weathering but also to its appearance. In many areas of Portugal, granite is an important source of wealth, employing a significant amount of labour (much of which is qualified). The rock is mined, transformed and exported to various markets, thus contributing to the currency inflows. (Gonçalves, 2010). For the commercialization of natural stone, it is necessary to evaluate its physical and mechanical properties in order to estimate the capability of these materials to be used in the above applications as well as to estimate the durability of surface finishes (Shehata et al.,1990; Sousa et al., 2012). This works prese nts “Branco Micaela” granite with several types of surface finishing’s that are usually applied. In this paper the colour and gloss are determined as a function of the different surface treatments.

2.

Experimental

2.1. “Branco Micaela” Granite Branco Micaela granite is white granite being chosen for this work due to its commercial interest to the company “ Transgranitos ” , but also because of the ease of obtaining samples and the wide use of this product mainly in construction applications. The quarry from which this granite is extracted is located in Carapito (Rei Mouro), in the municipality of Aguiar da Beira, district of Guarda. (Gonçalves et al. 2019)

Fig.1 - Satellite image of the Granite Branco Micaela quarry (quarry owned by Transgranitos) Coordinates: 40 ° 45'46.2 "N 7 ° 29'14.8" W This kind of granite consists essentially of quartz, feldspar, plagioclase, muscovite, hematite, apatite, zirconium and carbonate as it may be observed in table 1, which shows mineral composite of the used material.