Is additive construction (AC) sustainable? Many companies in the industry claim this is for many reasons. They claim it reduces waste because builders can only print what they need for particular projects. They also say that using 3D printing for construction can reduce emissions by reducing or eliminating instances requiring heavy construction equipment or trucks to bring supplies to construction sites. Here, we take a closer look at these claims.
Reduce waste with construction 3D printing
Waste reduction is an established benefit of 3D printed homes or buildings, provided the companies overseeing the projects have invested the time and talent in perfecting their processes. Consider, for example, Mighty Buildings. His approaches eliminated almost all excess construction waste. The base size of these modular structures is 350 square feet, although customers can use two together, resulting in a size of 700 square feet.
In another case, a team 3D printed an eco-habitat in Italy made from locally sourced clay. They also indicated that people could modify their methods to make them compatible with other types of raw earth found elsewhere. In addition to providing the waste reduction associated with readily available materials, this process promotes recyclability and supports people in need of climate-resilient housing.
Unsecured emission reductions
In the manufacturing industry, companies often use specialty industrial gases to improve the quality and appearance of certain materials. Many outcomes affect the construction industry.
For example, hydrogen-nitrogen mixtures can make metals harder, while krypton and argon are widely used in glazed windows that promote thermal efficiency. Similarly, some site activities, such as welding, emit gases. However, people are generally much more concerned about emissions related to concrete.
Statistics point to concrete causes of about 8% of global carbon dioxide emissions. So manufacturers are exploring viable ways to reduce or eliminate society’s reliance on this hugely popular building material. In a similar vein, interested parties are investigating how to replace polyurethane with cellulose when choosing building insulation due to the significant greenhouse gases associated with the production of the latter.
Many people may assume that the materials used in 3D printing construction are automatically superior in terms of emissions. However, this is not necessarily true. Most 3D printed houses still use cement in their construction. More sustainable alternatives do exist, however. In one case, Hyperion Robotics combines automation and 3D printing with low-carbon concrete in its AC process, claiming it uses up to 75% less concrete than in conventional construction. This approach reduces both the materials used and the greenhouse gases emitted.
People particularly concerned about the durability of 3D printing should always check what materials the companies involved use. They should also confirm associated emissions against conventional materials and practices, including whether the process involves transport-related emissions. This makes it easier to analyze whether 3D printing is really a more sustainable construction method.
Taking the sustainability of additive construction to new heights
One of the positive results of the intersection of 3D printing and construction is that companies and researchers are constantly looking for innovative ways to make it more sustainable. Consider the work of researchers at Texas A&M University. They created a new material called hemp concrete for 3D printing buildings. The team said they made a material with a negative carbon balance, derived mainly from hemp, which offers excellent fire resistance and thermal insulation properties.
Elsewhere, a group of researchers from Singapore have used recycled glass as a substitute for sand in 3D printing. They demonstrated the concept by 3D printing a concrete bench with the new mix. This option isn’t widespread enough to be viable for homes or other buildings, but the potential gives people reason to be hopeful.
Azure Printed Homes uses recycled plastics for up to 60% of the materials in its initiatives. It’s an attractive method that keeps discarded materials out of landfills, giving them a new purpose.
Sustainable 3D printing can also extend to what is inside a building or on a construction site. A company is using pellets made from agricultural waste to create 3D-printed lights. Another group 3D printed portable toilets from single-use medical plastic. Could this example pave the way for reducing emissions from conventional portable toilets brought to construction sites? Only time will tell.
Building 3D printing is more durable in many ways, but not all
Stating that 3D printing is always more sustainable than conventional construction methods is certainly too broad a statement. This is most likely from a waste reduction perspective, provided the parties involved have perfected their processes and eliminated any inefficiencies.
However, since most 3D printing materials still use concrete, there is more than enough room for improvement. It should also be noted that many of the sustainable alternatives mentioned here are still so new that they are not yet widely used, and some are still in the design phase.
It might become apparent later that some materials are not as durable as previously thought. If such projects then require extensive redesigns after just a few years, they might prove less sustainable in the long run than homes built without 3D printing.
Image courtesy of Twente Additive Manufacturing.
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