Earth construction finds a way to utilise additive manufacturing technologies to build structures from biodegradable, natural materials. In construction and digital fabrication non-biodegradeable materials are commonly used. But if we are to create new architecture can we adapt these processes to create structures that are as natural as possible. Maeid has used robotic-additive manufacturing technologies to create high-resolution three-dimensional printed structures from soil. Allowing the structures to become part of the environment, where nature can flourish around or upon them.

Additive manufacturing is a technology that became very popular within the last 10 years with the maker movement, with cheaper 3D printers coming onto the market, allowing almost anybody to create 3D prints from home. But with this came a problem. Although 3D printing allows less waste to be generated through the products internal construction, and lack of material for molds etc, these 3D prints were usually made from plastics and their binders can also be toxic. This in turn created a large amount of waste as people printed objects due to the novelty. But as time has passed people are using these technologies in novel, and more sustainable ways. 

The Project

Soil has long been used as a building material due to its availability and low cost. These types of construction have now been adapted by architects as a way of creating more sustainable structures. There are different types of earth architecture, which includes rammed earth, where soil is compressed into walls. The mud used in older forms of soil buildings is usually combined with  synthetic or natural fibres such as straw. Examples of these types of buildings include the settlement of Ait-Ben-Haddou in southern Morocco and the Mugsum Mud Huts in Cameroon. These structures are beneficial in many different conditions as they respond to temperature, humidity, and seasonal change. They also blend into the environment which can be beneficial for wildlife. Even though these are much more sustainable than most other construction methods, they can use a large amount of water. Also, due to current construction methods only simplified shapes can be produced. 

Maeid has created a process of using a robotic binder-jetting process to create organic bio-composites to overcome such limitations of common earth constructions.The team was able to create complex three-dimensional geometries from soil. Their research also looked at how biological polymers, such as polysaccharides-based hydrogels, can be used as sustainable, biodegradable binding agents. The combination of the soil and hydrogels shows potential for a completely reversible construction process for full-scale architectural implementations. Robotic additive manufacturing has been shown as a way to improve the current limitations of constructing with earth, by allowing for complex organic shapes and overhangs. 

The Process

The additive manufacturing process implemented by Maeid uses hydrogels as biodegradable binders to solidify the soil for compact material deposition. Binder jet printing is used to create these structures. This process uses a liquid binding agent which is despositied onto a bed full of a powder, determined by a predefinated computer designed 3D form. Cross sections of the desired shape are created, which are then built upon layer by layer. This type of printing is used as it allows for the possibility of large scale objects with complex geometries to be made. Between each printing layer loose organic soil is spread over the deposited hydrogel manually. The layer is then pressed and contained into a boundary box. This process is then repeated until the structure is complete, and then left to cure for 24 hours. Once hardened, the bounding frames are released and the 3D structure is excavated. 

As well as researching the best methods of creating soil structures, Maeid explored types of biodegradable binders. Within 3D printing this can be an issue as the binders can be extremely toxic. Their research led them to using hydrogels which are water-based bio-polymers. These materials are used in tissue engineering and biocompatible scaffolds. The particular hydrogels that they used are polysaccharide agarose combined with agaropectin. Different ratios of hydrogels were deposited to increase the structure’s mechanical properties. They found that the higher concentration of hydrogels corresponds with a higher mechanical capability. In conclusion, their research showed that hydrogels are suitable for the binding process as they allow for different material properties and a temperature, humidity, and time-sensitive type of deposition. 

Their research was split into 3 sections:

• Mechanical: levels of compactness influence the mechanical properties of soil 
• Physical: sieving or mixing of soil types can change its physical parameters 
• Chemical: addition of chemical compounds, such as binding agents, can be used to change soil qualities 

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Applications

As proof of concept, Maeid created structures within a room for the 2018 Ars Electronica Festival in Linz. A large fully biodegradable immersive architectural structure was printed for the installation. The structures, although printed off-site, were excavated live during the festival and were made out of 40 tons and 28 m3 of robotically 3D printed soil. The aim of this installation was to showcase the potential to achieve highly complex geometries, as it was the first immersive space solely created out of 3D printed soil.

Maeid also used this technology the following year in an installation for the RHS Chelsea Flower Show at the pavilion GARDENING WILL SAVE THE WORLD – IKEA & TOM DIXON. This installation was called ‘Terrestrial Reef‘ and was a 21st century techno-organic garden of natural and synthetic elements, which included soil, fungi and robots. The hybrid garden was 3D printed from soil and aimed to look at the relationship between the built environment with the natural environment as defined by western modernity. Exploring what the implications and opportunities are in decision making for landscapes and gardens shaped by Ai strategies and machines.

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References:

MAEID