Outside of the additive manufacturing (AM) industry, one will often see the concept of additive construction referred to as “house 3D printing” or “3D printed construction”. Just see Google results
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keyword tool below. This in part indicates the level of mainstream awareness of this specific industry, as most mainstream news stories cover the growing number of homes currently being made with concrete 3D printing techniques. However, additive construction is now reaching a point where the sector is valued for 3D printed housing and beyond.

Additive construction has finally done it

This is signaled by a number of developments, primarily the number of hugely important players that have entered the space. Many of the headlines we see today are generated by small startups, including ICON and COBOD, that build construction 3D printing systems. However, their customers are some of the largest on the planet.

For example, COBOD—supported by the $1.8 billion PERI Group is the supplier to GE, which recently built the world’s largest additive construction facility to 3D print concrete bases for wind turbines. About $28 billion cement giant Holcim in hot water for manufacturing offers with ISIS in Syria, is another COBOD client. He uses COBOD machines to 3D print homes and schools in Africa through his non-profit group 14trees.

ICON’s customers are arguably even bigger. In addition to working with smaller real estate developers, ICON’s main partners are NASA and the US Department of Defense. For the US Army, ICON 3D printed vehicle shelters and massive barracks.

Meanwhile, other conglomerates are entering the industry, including CEMEXthe 5th largest building materials company in the world; Sika, a Swiss chemical giant with a current market capitalization of $38 billion; and Saint Gobainone of the oldest and largest multinational building materials companies in the world, with revenues of approximately $47 billion.

Where does additive construction come from?

Wohlers Associates, powered by ASTM International, is the oldest and most respected consulting firm in the 3D printing industry. In April 2022, construction 3D printing expert Stephane Mansour joined Wohlers as an associate consultant, offering another sign that additive construction had succeeded. We know construction 3D printing is more than just “home 3D printing”, but where did it come from? Mansour had answers.

According to the specialist, additive construction has received a significant boost from the Middle East, where the United Arab Emirates announced its Vision 2030 and Saudi Arabia unveiled its NEOM project. The first sought to 25 percent 3D-printed Dubai buildings by 2030, while the latter is injecting $500 billion for planning and construction from Saudi Arabia’s Public Investment Fund and international investors.

“In response, general contractors launched efforts to further investigate and realize a construction addendum as a tool to achieve the required goals,” Mansour said. “Notable companies and key players in the Gulf region included BAM Infra, BESIX, Freyssinet, Vinci, ACCIONA and Consolidated Contractors Company. The European advances and achievements in the field of construction additives over the last six years are the direct result of the companies mentioned above. Based in Europe and working in collaboration with various material suppliers, technical institutions and construction 3D printing startups, they seek to realize construction additives as a tool in the sector.

This was further driven by a combination of the effects of the pandemic and the negative impact that traditional building technologies have had on our ecosystem. According to Mansour, issues such as supply chain gaps, shrinking workforce, growing construction demand, rising material costs and customer sustainability costs are “pushing the AEC sector to rethink the status quo and move towards building additives”.

What’s next for construction 3D printing?

As this increased adoption continues, two key areas represent the next stage of additive construction development, according to Mansour: improving the technology and making it more sustainable. In the first area, we will see features such as automated print monitoring through the use of sensors and artificial intelligence used to improve print quality. In addition, the commissioning and decommissioning process of 3D printing equipment, especially for on-site printing, will be optimized.

As for sustainability, we already know that if the cement industry were a country, it would be the third largest emitter of carbon dioxide in the world after China and the American Mansour projects have reduced the dependence on this material in favor of metakaolin, adobe, limestone, recycled construction waste, mine tailings, shales, etc. Likewise, new reinforcement materials will be explored, including hemp and hemp rebar, graphene, integrated fibers and glass aggregates.

Of course, additive construction is not only used for 3D printing concrete houses, nor will it be in the future. Mansour pointed to a number of applications beyond what is covered in most mainstream media, such as digital inventory to address overhead, deadlines and logistics; optimize 3D printing parts and spares for aging construction equipment; more sustainable methods for creating facades, claddings and structural connectors; and implementing a circular approach by using recycled materials like plastics and wood waste for 3D printing furniture and accessories.

Additive building standards

Going forward, the biggest hurdle for the industry may not be technological in nature, but associated with additive building standards.

“Nothing in construction is done without standards. There is no “redoing” in construction; a structure must be built to be safe and to stand the test of time and the elements. The construction industry is not averse to adopting new approaches and technologies, but needs to be assured that “printed” structures are safe and meet or exceed requirements. This is where standards play a crucial role,” Mansour said. “Standards allow for mass adoption and acceptance, which helps create a healthy competitive marketplace that encourages new developments in materials and approaches, and enables competitive pricing.”

For this reason, Mansour took it upon himself to create a committee to address the issue in March 2021. What became the ISO/TC 261/JG 80 committee developed a draft standard, ISO/ASTM 52939is expected to undergo a second review and comment process before official publication by the end of 2022.

“This is very timely, as it fits into several government-led initiatives, such as the European Commission’s recent proposal of March 30^e2022 where the construction additive is explicitly addressed and where the European Committee for Standardization (CEN and CENELEC) approved the adoption of ISO/ASTM 52939 as a CEN ISO/ASTM standard when published,” Mansour noted.

As we have seen with other 3D printing standards, this is just the beginning of a long and painstaking process that will be essential to move the industry forward. With this key work underway, other efforts needed to advance additive construction will be the ongoing education of industry professionals. In this regard, Wohlers Associates, powered by ASTM International, will advise and support the global construction industry in understanding the strengths and limitations of 3D printing as a tool. The organization provides a strategic perspective on processes, materials, regulatory initiatives, and the development and adoption of industry standards.