With over 500 quarrying sites, France offers a vast diversity of stones, all governed by the NF B10-601 standard. This standard allows for the assessment of each stone’s characteristics (friability, porosity, pull-out resistance, etc.) according to its final destination in the structure, complementing installation guidelines. Natural stone is experiencing a resurgence of interest, particularly for façades. Indeed, this geo-sourced material possesses numerous assets: durability, natural appearance, and architectural qualities. Arcora dedicates a specific line of research to stone within the Lab, Arcora’s R&D unit. The teams have worked on the classification of different stone types, allowing for a more refined knowledge of the material.
Reasoned Environmental Impact
Beyond geographical origin, numerous criteria form the environmental impact of a stone variety: extraction method, hardness (leading to cutting resistance), and machining, particularly regarding the energy mix used by the factory. Arcora studies this entire supply chain to offer the lowest possible carbon solutions while meeting architectural and economic requirements, as well as implementation constraints.
[Selection of stones such as Vosges Sandstone (Pierre Champenay / Pierre Rothbach / Pierre Rouge Adam), with different associated finishes, as an alternative to Red Agra stone (India).]
Attached Stone – Supporting Non-Traditional Practices
Arcora conducts research on the characteristics of each stone, as well as on the interface with the façade and the structure, taking into account the weight of the stones, the rigidity of the fasteners, and the evolution of the different materials constituting the façade.
For example, Arcora led the design of a sub-structure allowing stone attachment onto an aluminum block façade; thus moving away from the traditional technique of installation on concrete to incorporate stone onto a lightweight façade design.
The diagram below is part of a heritage rehabilitation project, in which the original stones did not allow for use as attached stones—the system best suited to the project’s constraints. Different solutions were developed by Arcora, largely non-traditional, to allow for the implementation of the stones in compliance with the established specifications, in accordance with modern standards, and while respecting the building’s aesthetics.
Alternative Techniques Proposed