Environmental impact of sandstone ornamental stones from a Belgian quarry

Since 1990, the association Pierres et Marbres de Wallonie (P&M) has been promoting ornamental rocks from Wallonia in Belgium and abroad. It is supported by the Walloon Region and the Walloon Export Agency (AWEX). It brings together some thirty member quarries that exploit some fifteen different materials.
In the framework of sustainable development and the necessity of product labelling in a standardised framework, P&M is in the process of developing several B-EPD (Belgian EPD) to integrate the Belgian sustainability tool for construction works TOTEM (Tool to Optimise the Total Environmental impact of Materials).
The fist two products come from the Grès du Bois d'Anthisnes quarry (Poulseur, BE), exploited since the 19th century. This sandstone is exceptionally hard and requires no maintenance. It can be used for all types of stonework, facing stones, slabs and paving stones and has undeniable advantages for the construction of private or public buildings and private houses. It is also ideal for interior and exterior decoration (garden, paving, pond stones, etc.).
One is a "pavé platine", a square sandstone cobble that has been first sawed, and then manually cleaved and retouched in order to rectify the edges of the visible face so that they lie in the same plane (pinching) and are perpendicular to each other, thus giving the visible face a shape approximating to a square (squaring). The sandstone product used in this study is a 15 cm x 15 cm square exterior platinum block with an average thickness of 8.5 cm. It is used for pavement of sidewalks or roads.
The second one is a rough cleaved rubble, that is a cleaved (machine-split) stones, more or less rectangular in shape, maintaining a relatively rough finish and use for the external wall cladding.
The life cycle assessment (LCA) is carried in accordance with the standard EN 15804:2012+A2:2019, and the results show the very good environmental performance of these products. Moreover, the paving stones and the cleaved rubbles have a very long reference service life and can be reused up to seven times. This reuse at the end of their life when possible, or their recycling (as crushed aggregates) if they are damaged, allows for significant environmental gains when considering the whole life cycle and the benefits beyond borders.
Sensitivity analysis shows the major interest of the use of local stone compared to long-distance imports form India or China.