Stone-Ideas.com 
In a separate report, we describe the concept of Studio Gang architects for the University of Chicago’s new John W. Boyer Center in Paris https://www.stone-ideas.com/119928/stonesticks-for-natural-stone-facades/.
“StoneSticks” is a new building product reminiscent of elongated chopsticks. These are thin columns made of natural stone, which the architecture firm Studio Gang used to design the façade of the John W. Boyer Center in Paris. They serve as a brise soleil or protection from sunlight. Depending on the use of the interior spaces, they are positioned at varying distances from one another.
Originally, stainless steel cores were planned for the columns. However, at lengths of up to eight meters, this could have led to problems with deformation. The French company Mineral Expertise, known for innovative ideas for the use of natural stone, presented an innovative solution: The columns would have a fiberglass tube inside and two stone half-shells on the outside.
Carbon fibers were also used in some of the thinner sections.
The half-shells were sawed to a thickness of 10 millimeters using CNC machines. “Each piece underwent precise calibration, crucial to meet the project’s very tight tolerances and to allow perfect assembly around the composite tubes,” as the architects write in a PDF.
The limestone used, Saint-Maximin (Oise), came from a quarry just 40 km from the construction site. The raw blocks were meticulously selected according to their mechanical and aesthetic properties.
The prototypes of the small columns underwent 18 tests: bending, shear, bonding strength, thermal expansion, impact resistance, fire performance, and vibration behavior.
Special techniques also had to be developed for installing the StoneSticks: They are “held at the top by a threaded stainless-steel rod and supported at the bottom by a dilating, anti-vibration bearing”, writes Mineral Expertise in a PDF.
801 columns were manufactured.
Mineral Expertise lists the advantages of the StoneSticks:
• 40% reduction in the quantity of stone used,
• lighter components with equivalent performance,
• 25% lower cost compared to a stainless-steel solution.
The title of the PDF states Mineral Expertise’s general motto: “Reinventing Stone in Contemporary Architecture.”
Participating enterprises:
Cluster Méca: integration of composite materials with Eurocodes.
GDP Composites (Angoulême): manufacturing of the 801 fiber-reinforced tubes.
Aldo Pesetti (Pietrasanta): shaping of the stone shells.
CSTB Nantes wind tunnel: validated resistance to wind up to 150 km/h and tested acoustics.