The ICD Aggregate Pavilion 2015 by the University of Stuttgart’s Institute for Computational Design (ICD: Institut für computerbasiertes Entwerfen) is the first architectural structure to be publically realized with a designed granular system. The individual grains of these aggregates are geometrically defined to interlock and consequently require no additional binding agent. The pavilion was constructed and exhibited during mid-2015 in a central location within the University of Stuttgart campus.

“In a designed granular system the individual particle is custom designed to exhibit a specific behavior, and in this case we were aiming to develop designed granules which allow for building vertical structures that do not need additional formwork,” explains Karola Dierichs, researcher at the ICD and project author.

These synthetic granular systems are an emerging area of architectural design research. Designed granulates are particle systems with large numbers in which the individual granules are synthetically made and geometrically defined. Defining the geometry of the individual grains makes the aggregate a programmable matter, which has properties that cannot be found in naturally-occurring granulates such as sand or gravel. This physical property enables structures built from these granulates to be fully recyclable, and during construction can be rapidly poured into multiple spatial formations and adapted to almost any site constraints.

The focus of the ICD Aggregate Pavilion 2015 has been the exploration of programmed verticality (staking), a feature that transcends the natural granular angle of repose. Furthermore, the structure is functionally graded using three different types of aggregates that can be deployed in difference zones of vertical structures to accommodate load transfer that increases from top to bottom.

The ICD has investigated the structures and also a range of possible construction and grading techniques using scale models and 1:1 prototyping in a factory environment. Distinct-Element Modeling (DEM) simulations that allow both for predictive and analytic modeling of particle systems with very high numbers have complemented testing. To build the towers that form the pavilion, the team programmed a cable robot to drop small clusters of the granules in specific areas based on their research into possible construction and grading techniques.

The cable robot was custom-designed as a large-scale robotic system that can be adjusted according to site conditions and dimensions, with a maximum range of 30 meters. The system was adjusted to the site and fixed to four surrounding trees after initial testing within a confined framework. Onsite calibration allowed for precise placement of the granular material by the robot within the construction area. The structures could be constructed and re-constructed in situ.

A total of 30,000 particles were injection molded using recycled plastics sourced from local industry. Two or three variations of a geometric granule type based on a single parametric model were used in construction to accommodate different structural requirements.

The entire structure was constructed without formwork in a few hours, and reconstructed multiple times during the exhibition period. The cable robot achieved accuracy within the range of a few centimeters across the construction space of a seven-meter square, with a payload of one kilogram.

Institute for Computational Design (ICD)

Karola Dierichs, Achim Menges

Design Team

Giulio Brugnaro, Matthias Helmreich, Ondrej Kyjanek, Gergana Rusenova, Emily Scoones, Leyla Yunis

Cable Robotics

Martin Loucka, Ondrej Kyjanek

Manufacturing

Wilhelm Weber GmbH & Co. KG

Funding

Holcim Awards for Sustainable Construction, ITASCA Consulting Inc.