In our most recent roundup of 3D printing webinars and events, we told you about the free “Let’s Talk Concrete 3D Printing: A Multidisciplinary Approach” webinar by Spanish company ACCIONA. The webinar, held the morning of June 30, lasted about 100 minutes and focused on the use of 3D concrete printing (3DCP) technology in the value chain. Several speakers presented their viewpoints about the topic.
International contractor ACCIONA is nearly 100 years old, and works to develop infrastructure. The company is focused on sustainability, and claims to have been carbon-neutral since 2016. ACCIONA COO of 3D Printing Luis Clemente introduced the first speaker, Carlos Egea, Manager at ACCIONA’s 3D Printing Skill Center in Madrid.
He explained that 3D printing innovation is based on three things: the machine, the material, and the design. Egea noted that 3D printing can fabricate “impossible forms and shapes,” and said that, while ACCIONA has also used powder bed technology, the company is now working on extrusion processes, with a focus on concrete, which can make all sorts of things, like walls, bridges, and staircases.
He mentioned the company’s 6 x 3 x 2 cubic meter “beast of a printer,” a massive powder bed system which resides at its recently opened global 3D printing center in Dubai, as well as a few concrete 3D printing projects that ACCIONA has worked on, including a pedestrian bridge and a staircase created with generative design.
“Every technology has its own material,” Egea said. “Because of the different characteristics of every one, the same material could not be used. Even if you’re talking about concrete, it’s not the same concrete used in powder bed as is used in extrusion.”
He finished by saying that, through ACCIONA’s various partners, the company is also working with sand, metal, resin, and microplastic 3D printing.
Alaa K. Ashmawy, PhD, P.E., Dean and Professor for the School of Engineering at the American University in Dubai, next discussed 3DCP from an academic point of view. He explained that he would be talking about the following:
- 3D concrete as an evolving technology
- the role of higher education institutions
- challenges in research and education
- current efforts
- future direction of 3DCP
Ashmawy stated that without industrial machinery, automation and control, “it would be impossible to achieve what we’re trying to achieve” in terms of digital construction, but that computer aided design/building information modeling is the most important part. He next provided a brief history of 3DCP, mentioning that Loughborough University researchers built a prototype of a 3D concrete printing gantry system between 2003 and 2005, the latter of which is the same year that Italian inventor Enrico Dini patented D-Shape, or powder bed construction technology.
In 2008, Loughborough replaced its gantry system with robotic arm technology, which offers more flexibility, and the first prototypes of houses built from hybrid components (i.e. a combination of 3D-printed and pre-cast) were built in 2015. That same year, Dubai announced its intention to build the world’s first 3D-printed office building, and the Office of the Future was inaugurated and opened in 2016. Now, the technology is continuing to gain momentum in the UAE, Russia, the Netherlands, and China.
Ashmawy detailed where 3DCP stands on the Gartner Hype Cycle for Emerging Technologies, stating that he believes 3DCP will likely reach the Plateau of Productivity in the next 5-10 years, or even sooner, once the industry gets over the idea of fully finished 3D-printed houses and begins focusing on more realistic uses for concrete 3D printing in the construction sector.
Moving on to the role of universities in 3DCP, Ashmawy believes it’s very important to educate students on this technology, and work on important materials and automation research, to help bridge the gap between academia, industry, and municipalities, “educating the community at large about the technology.” He listed several 3DCP-related research challenges, including how to optimize the automation process, monitoring and control, expenses, and, finally, materials and environmental factors, because it is still necessary to worry about how the speed and quality of construction is affected by things like humidity, wind, and temperature, even if you do have the optimal material.
“These research challenges should be what we’re educating about,” Ashmawy stated.
As for current efforts in 3DCP, he mentioned that China is working on computing, among other factors, while Europe focuses on robotics, commercialization, rheology, additives, and extrusion and the UAE works on mix design, layer bonding, pumpability, and local resources.
“We need to look at optimizing the mix design and the print process to minimize cracks and defects,” Ashmawy said about the future direction of 3DCP, mentioning that it was also important to investigate how to lower costs, adapt systems for multi-story construction, 3D print load-bearing elements, automate quality control and assurance, and integrate non-structural features, like electrical wiring and plumbing.
Autodesk Senior Product Manager Sualp Ozel spoke next, and discussed how the company participates in large-scale and concrete 3D printing, stating that Autodesk “makes software for people who make things,” like smartphones, special effects for movies, and skyscrapers. He provided an overview of what Autodesk offers for additive manufacturing, such as design and simulation software Netfabb, CAM solution PowerMill, and the CAD/CAM/CAE tool Fusion 360, which “connects the entire product development process into one cloud-based platform.”
“To support development of all these tools, we have an additive manufacturing research team inside Autodesk,” Ozel stated.
He noted that additive manufacturing is no longer solely used for prototyping, but is a production-proven technology, just as robots are no longer constrained to the factory floor, but moving out to construction sites. Ozel then listed a few case study examples of how its technology has been combined with 3D printing to create innovations, such as wind turbine molds, a BMX bike frame, a ship’s propeller, concrete barriers, and a concrete bench at the Autodesk technology center in Birmingham.
Ozel also showed another interesting example of concrete 3D printing: a unique wraparound staircase created with generative design and 3D printed by ACCIONA.
Fahmi Al Shawwa, the CEO of Immensa Additive Manufacturing, was unable to make it, so the company’s COO Axel Fernandes and Business Development Engineer Jana Hamadeh stepped in. Immensa was founded in 2016 as the first privately owned UAE company to specialize in 3D printing, and Fernandes said that “it’s the only regional company covering the additive manufacturing process from end to end.”
Some of the examples he gave of ACCIONA’s construction projects are precast molds for concrete structures, profile molds for chamfer edges, and concrete rebar caps. Hamadeh mentioned a really interesting Immensa project: a Smart Concrete Wall built in collaboration with BigRep and Consolidated Contracting Company (CCC) that was made using 3D-printed molds and featured embedded touch sensors installed after the molds were removed.
Fernandes listed some other construction projects the company has worked on, like a large 3D printed monumental structure, decorative wall panels and partitions, architectural models, interior fit-out elements like furniture, and custom 3D printed air conditioning grills.
Clemente was running the show, and spoke last, mentioning again the largest powder bed 3D printer that’s installed at ACCIONA’s 3D printing facility in Dubai, of which he is in charge.
“Our positioning is to become a provider of large-scale 3D printing multi-technology solutions for the construction sector,” he stated.
He explained that ACCIONA uses concrete 3D printing for three main construction applications, the first of which is civil engineering and buildings. He listed a few examples, like a project in Dubai involving tall road columns, the generatively designed staircase with Autodesk, and the pedestrian bridge in Madrid, which was designed by the Institute for Advanced Architecture of Catalonia (IAAC) and 3D printed by ACCIONA in eight segments, before it was installed as a pre-cast element in a single piece.
“We had to comply with a lot of regulations, since the public walks on it,” Clemente said, mentioning that parametric design was used to help create the bridge.
The second application is urban spaces, and examples include an artificial coral reef, a planter, and a bench in Dubai with a polished finish. He also mentioned a modulated wall at the IAAC with “a very intricate shape,” and a bus station, both of which relied on the “freedom of shape” that 3D printing ensures.
ACCIONA’s final construction application for concrete 3D printing is historical and cultural heritage conservation.
“We’re very proud, as this can add a lot of value,” Clemente noted about this application.
As an example, he explained that the company worked with the National Archaeological Museum in Spain to make a 2.2 x 3.3 m 3D-printed replica of the Romanesque Arch of San Pedro de las Dueñas, which stands in the museum’s garden. Clemente also said that the company is working on a proposal for a 3D-printed concrete replica of another existing arch, though it is not yet complete.
Companies all around the world today are 3D printing with concrete, not only to enjoy the typical benefits of additive manufacturing, like faster speed, sustainability, and lower costs, but also to harness the ability to create complex geometries, so that concrete structures not possible to build with conventional manufacturing methods can now be realized. However, it’s not an exact science yet, and research continues into how best to optimize the material for the AM applications which can most benefit from its use. That’s why these kinds of webinars are so important, so that attendees can learn from experts about what the technology is truly capable of creating.
(Images: ACCIONA webinar screenshots)
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