Wednesday, September 13, 2017

The Cost-Effective Characteristics Of Additive Construction Techniques

I've been waiting excitedly all Summer to return to the topic of architectural 3D-printing. Finally the latest news coalesced into something of a coherent point about where this technology is going. I first wrote about the above friendly-looking MIT-created robot earlier this year, and it continues to be a convenient reference point from which to start our story: Construction drones and 3D printing are converging in ways nobody expected.

The design studio is still responsible for the design, but the algorithms used in its construction challenge the traditional architecture or engineering firm with a very particular type of expertise. It's a gap in skills I'm not sure exactly how best to respond to; except perhaps to invite in a 3rd-party. In time, machine learning will no doubt come to have a dominant role in streamlining the significant amount of processing needed to make designs machine-readable by construction drones. Some thought will also need to be put into the large geospatial datasets which have now come to represent the construction site, and the structure's coordination within it, because this process has emerged as an area of expertise. Construction drones et al. have to know where they are in 3-dimensions in order to be effective. These challenges might seem daunting to traditional firms, but in reality represent the strengths of digital technology. MIT's research, once refined and commercialized, will offer significant cost savings and increased accuracy when deployed. The construction site might ultimately come to have less people on it, but one, those are the client's savings, and two, lets not forget this shift is creating jobs too, just elsewhere. Getting back to my main point that additive construction techniques are more cost-effective, I argue that firms who start to learn and develop expertise in these areas will begin to gain a competitive advantage against others in the marketplace by potentially offering a cheaper building on a per square foot basis.

A good analogy for why additive construction techniques are so cost-effective can be seen in the use of 3D-printed sand cores in the metal forging industry. ExOne and Voxeljet are two such companies offering the service. Complex sand cores can be built up of whatever component the client needs greatly shortening the production cycle for the final part. There are also active projects researching methods of printing metal directly from a metal-based ceramic-polymer or powder. FromLabs is probably the best known but the field is competitive and many different companies are growing quickly. The fascinating thing about 3D printed metal is how it's managed to advance the subject of material science itself. With all the innovation that's occurring in the field, materials have started to emerge that blur the lines between what is a metal, ceramic or plastic. Australia's Swinburne University of Technology's recent work refining the cementitious material mixture used in architectural 3D printers shows promising results in this vein. The process uses sand and various polymers to create a 3D printed material that shares many characteristics in common with sandstone, but with the added benefit of allowing customization to better suite the goals of the project. Scaling up, D-shape is a UK-based company trying to achieve structural 3D printed concrete. Again – very exciting technology – but limited by its structural qualities. Cementitious 3D printing has the advantage of not requiring formwork, saving both time and materials, and highlighting the fundamental cost-effectiveness of additive construction techniques.

Another way 3D printing is fermenting radical change in architecture is by opening up the possibility of new architectural forms. Again we turn to MIT to reference developments in a new type of structural system made possible (or at least made greatly easier) with 3D printing. Force-line structures have a healthy background in applied mathematics and engineering, but now find expression on the construction site through MIT's research on Stress Line Additive Manufacturing (SLAM). Precise placement of the extruded 3D printed material is key to these structures' strength. With time, methods can be found to optimize material usage and that, combined with the lack of formwork, potentially makes the technology very cost-effective to deploy.

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