Aleatory architecture explores new approaches and concepts at the intersection of granular materials research and architecture/structural engineering. It explicitly includes stochastic (re-) configuration of individual structural elements. It thereby disrupts the traditional assumptions about the authority of the architect as planner as well as the typical hierarchy of the design process. Aleatory architecture suggests that building materials and components can have their own agency — that they can be “designed” to adapt and to find their own responses to structural or spatial contexts.

In this way the very meaning of “design” is brought forward for reconsideration (though not abandonment): Can there be design by disorder? What are the possibilities of material agency? Can we develop a vocabulary of concepts to interpret various orderings of chance?  In the paper listed below we introduce some of the key ideas and investigate these questions from a range of different scientific and architectural perspectives.

1. •Sean Keller and Heinrich M. Jaeger, Aleatory Architectures. preprint
   

In classical Latin, ālea refers to a die or dice, and so āleātōrius means “connected to gambling.” In modern usage, “aleatory” became an important concept in mid-twentieth century avant-garde art—especially music, where many varieties of indeterminate composition and performance were explored. For example, John Cage’s seminal Music of Changes (1951) demonstrates how chance devices of some sort—rolling dice, flipping coins, shuffling cards, dropping sticks—can be used to generate a musical score, thereby weakening the role of the composer (as well as the preconceptions of the performer and listeners). What we consider here is how a similar exploration of chance’s role within composition might take place in architecture—emphasizing that this cannot be a simple copying of aleatory techniques already used in other fields, but requires a careful translation into the specific possibilities and restrictions of contemporary building.

Aleatory design is not intended to replace current building methods. Instead, it is meant to explore new options, expanding the range of possibilities. In many, perhaps most, cases aleatory construction may be combined with more traditional building elements such as spanning plates, tensile components, and enclosing membranes. Each approach can be used where it is most effective. What we are exploring here is whether new ideas could lead to new architectural structures based on granular, jamming-based construction. Thus, on the level of science and engineering we ask: How far can we push an aleatory conception of construction? What are the technological challenges and the eventual limits? And on the architectural level we ask: What is the emerging aleatory aesthetic and how can it be turned to architectural purposes?

For example, what if speed of construction and low material weight become more important than structural perfection or permanence? Speed certainly is a prime benefit of any approach based on granular matter: since no regular, ordered arrangement is required, granular structures can be simply poured into place. Using suitable particle shapes, low-packing-density and thus potentially lightweight structures can be envisioned. Since the constituent elements connect solely by interlocking and/or friction, such structures are not only formed very quickly, but also reconfigured and taken apart easily. Thus an aleatory approach based on granular matter challenges the traditional architectural notion of planning for structural permanence.

In 2012 we started to explore the physics of jamming-based architecture as par of the workshop Rigidity, Fluidity, Adaptability: Frontiers of Pure & Applied Jamming, which brought together physicists, engineers, and architects.

Some of these ideas led to a novel, robot-aided fabrication process for a large-scale architectural structures by Gramazio Kohler Research (ETH Zurich, Switzerland) in collaboration with the MIT Self-Assembly Lab. A first demonstration of this aleatory, jamming-based Rock Printing process was exhibited at the inaugural Chicago Architecture Biennial (October 2015-January 2016, at the Chicago Cultural Center downtown). Our Lab provided technical consultation. Click here for details.

images copyright: Gramazio Kohler Research

The key idea behind Rock Printing is to embed string with the granular material in order to provide tensile strength and enable small rocks to form tall structures with overhangs. An important consequence is that removal of the string collapses the rocks into a pile and thus completely recycles the building material, similar to unraveling a knitted sweater. The picture below is a snapshot from the de-installation process.

For a video of the de-installation event, with some of the filming done using our high-speed video camera, click here

image copyright: Gramazio Kohler Research

During the last couple years our Lab started to investigate to possibility of creating jamming-based aleatory structures without any confinement or added string, simply by using particle shapes that suitably entangle during pouring to be able to support a load. This then leads to the almost paradoxical outcome of a structure that is stable under compressive load but unstable when the load is removed (meaning it can be recycled simply by removing the load). For more details on this see this entry.

In collaboration with Chicago-based artist Dan Peterman we recently started work on large Z-shaped particles. The image below is from a test of the loadbearing capabilities of poured aggregates of these particles on Jan. 26, 2016 at the Experimental Station, with grad student Kieran Murphy standing on top of a column of Zs. This column was formed by randomly pouring the particles into a box-shaped mold created by four tables turned on their sides....you can see one of these tables in the far corner; the load was applied by stepping on top of the column and the tables were then removed. Note how a dense packing of entangled Z-particles is able to direct applied stresses primarily downward, making it possible to create vertical structures like columns or walls that are completely rigid and stable without any string, glue, fasteners or confining membranes.