Environmental performance of building materials: life cycle assessment of a typical Sicilian marble

The building sector is strategically important for achieving sustainability. Therefore, the improvement of energy and environmental performances are relevant targets because precious building materials such as marble have a significant impact on the environment. The aim of this paper is an analysis of a typical Sicilian marble (Perlato di Sicilia) to evaluate its energy and environmental performance. Marble plays an important role in the economy of Italy and has a global market share of 58% in terms of exports. For the main production areas of marble, relevant environmental performance data are missing except for one region (Tuscany—Massa e Carrara province). Perlato di Sicilia, the main marble of Custonaci (Sicily), has never been analyzed previously.

Life cycle assessment (LCA) according to ISO 14040/44 is applied to marble tiles and slabs. For the life cycle inventory, data were collected from a representative plant in the Custonaci basin. In this small area of 69 km², about 54 quarries and related cutting plants are concentrated. The impact assessment includes the following categories: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and photochemical oxidation (POCP), following the CML-IA baseline 2007.

The results of the impact assessment for 1 m³ of marble tiles are 314.8 kg CO_2eq of GWP, 1.19 kg SO_2eq of AP, 0.073 g PO_4---eq of EP, and 0.046 kg ethylene_eq of POCP. For slabs, the corresponding results were 200.1 kg CO_2eq of GWP, 0.77 kg SO_2eq of AP, 0.053 kg PO_4---eq of EP, and 0.029 kg ethylene_eq of POCP. The total embodied energy values of tiles and slabs are, respectively, 1,772 MJ/m³ and 1,168 MJ/m³. This comparison shows that tiles manufacturing has higher values of embodied energy and environmental performance indicators. The value of the Custonaci slabs is reasonable compared to the Carrara marble (mainly slabs), and the embodied energy value of which is between 698 MJ/m³ and 1,414 MJ/m³. The main contribution to the energy consumption is due to electricity demand: 80% for tiles and 75% for slabs. Moreover, a comparison with the European type I Ecolabel criteria for natural hard floor coverings has been carried out to understand the range of the environmental impacts of Perlato di Sicilia compared to the thresholds reported in European Decision 272/2002.

This study is the first LCA of a typical Sicilian marble. The environmental interventions of the Custonaci marble appear to be slightly higher than Carrara marble. The nature of Custonaci marble and the technology involved in its production have reached the same performance level as in Carrara. Nevertheless, Custonaci marble is on the way to being an environmentally friendly product, as is shown by the comparison with Ecolabel criteria. The hot spots determined in this study are: the amount of spoils produced during the extraction step, the disposal of sludge resulting from cutting and finishing directly in the sawmill, the lack of the water recycling treatment in the quarry itself (as outlined in the European Ecolabel criteria), and the high electricity consumption.