(February 2011) Important innovations for natural stone construction were recorded in two main areas in recent years: one pertains to the thickness – stone became thinner and thinner down to thicknesses of mere millimetres. The second refers to the surface dimension – stone surfaces used for tiles, e.g., became larger and larger. Recently a German company decided to add yet another innovative element – that of movement.
Kirchheimer Kalksteinwerke have developed a technology by which lamellae can be fabricated from stone thus allowing for room dividers at the press of a button or sun screening on a building’s façade.
Technical realization is close to completion in a variety of projects protected by a European patent. Of special interest: the stone sheathing. Seal of approval by the German office for material control has already been granted.
The forerunner for the idea was a lamella cladding in stone developed for a bank building in the city of Würzburg. For reasons of security, the surveillance authority required armour for the 12 cm wide stone slats resistant to high-spirited free-climbers.
CEO Peter Hofmann developed a reinforcement applied to the underside invisible to the beholder made of a V- or T-shaped groove routed in the stone into which an aluminium or steel V-rod is inserted varying in size depending on the strength of stone used.
With this application the idea of pivotal lamellae was not far – easy to attach a motor to the armouring, a technology long used in construction of Venetian blinds. The motor is hidden behind the lamellae frame and can pivot or move the lamellae to any position desired.
The prototype was built with 2 m long lamellae – being the maximum length available for shell limestone due to the maximum block size. Longer elements are possible in other types of stone. Window blinds are also conceivable made of stone as the lamellae can be applied vertically or horizontally.
Shell limestone is quarried by Kirchheimer Kalksteinwerke which gives it its name. Applications range from steps to flooring, from facades to works of art.
Kirchheimer Kalksteinwerke (KKW) (German)
Photos: Kirchheimer Kalksteinwerke
Facades in motion: