50 GRANDES SURFACES | REVUE TECHNIQUE LUXEMBOURGEOISE 4 | 2019
The DTC group is an interdisciplinary team of architects, structural engineers and computer scientists. We are exploring, researching and teaching innovative architecture and structural systems with wood and engineered wood products, enabled by digital technology and computational methods. A major research aim is to use digital design and production methods for more efficient structures, using less material thanks to smart geometry , as well as innovative rapid assembly for simple, fast and precise construction processes.
RECYCLESHELL_
Christopher Robeller, Junior Professor of Digital Timber Construction at University of Kaiserslautern
_DTC Recycleshell Demonstrator
_DTC Recycleshell Diemerstein Demonstrator, Algorithm-generated CAD model
Can we use digital technology to make high-tech structures from waste material? The production of modern crosslaminated timber (CLT) walls creates a large amount of offcuts for windows and doors. These cutouts are of a high, certified quality and valuable building material, but too small for regular building applications. The Recycleshell uses digital technology to turn these small elements into a high-performance, column-free roof structures, that can be quickly and precisely assembled on site thanks to an innovative rapid-assembly concept using hardwood connectors instead of metal. It is inspired by the way nature designs structures: Material is expensive, geometry is cheap. The optimised shell shape, which loads the large number of joints predominantly in compression, is approximated with planar facets made from flat CLT plates. On the 5th of September, a first recycleshell demonstrator was presented to the public in the Diemerstein Valley near Kaiserslautern. It is also the first project on the University of Kaiserslauterns new “timber construction research campus”. Speeches were given by the University President Prof. Dr. Helmut Schmidt, State Secretary Dr. Thomas Griese, County Council Chairman Theo Wieder, Mayor Eckhard Vogel and Jun. Prof. Dr. Christopher Robeller. The DTC recycleshell demonstrates an innovative construction system, that can be produced from the CLT cut offs (waste
material), which result from window and door cutouts in large amounts. Furthermore, the system is assembled entirely with wooden connectors, a combination of beech wedge connectors and beech dowels – completely without metal screws or bolts. The form fitting joints also act as assembly guides, no substructure was needed for the rapid and precise assembly of the structure. The demonstrator consists of 230 planar plate elements, its optimised shell form is essential for the construction system, since it loads the joints between the elements predominantly in compression. The element geometries and the direct output of the CNC production data has been designed and generated using a software developed by DTC. The production data was calculated so that the components could be manufactured fully automatically, with millimeter accuracy and cost-efficiency using stateof-the-art CNC technology of our project partner CLTech GmbH. The assembly is simple, fast and precise, as with LEGO, with the help of special X-Fix beech wood connectors, which were combined with wood dowels. The construction works entirely without metal connectors between the plates. The material-saving lightweight construction project at the interface of architecture, civil engineering, production engineering and computer science shows new ways of