Researchers, industry leaders partnering on 3D innovations

Researchers are developing a 3-D printer to manufacture concrete components for construction.

by JENNY JONES, ASCE

December 16, 2014 — Leading industry firms are partnering with researchers at Loughborough University in the United Kingdom to develop 3-D printing technology that will use robotic technology to print concrete building components for commercial use. The technology could allow architects and engineers to design projects with highly complex concrete elements without the high costs and limits of molds and formwork.

Skanska, a project development and construction firm headquartered in Stockholm, Sweden, with offices in the United Kingdom, is leading the partnership. The company is licensing concrete printing technology that Loughborough University researchers have already developed. With funding from the government, Simon Austin, Ph.D., CEng, a professor of structural engineering, and Richard Buswell, Ph.D., a senior lecturer in building services engineering, began developing additive manufacturing techniques for concrete in 2009 and have since used the technology, commonly known as 3-D printing, to develop several mock components.

Skanska plans to advance Austin and Buswell's research by building a new 3-D printer that will produce large-scale concrete components for actual construction projects. The firm has formed a research and development consortium with the London-based architecture firm Foster + Partners; Zurich, Switzerland-based ABB Group, an automation technologies firm; Cheshire, United Kingdom-based Buchan Concrete Solutions, a concrete products manufacturer; and Birmingham, United Kingdom-based Lafarge Tarmac, a materials supplier.

Xavier De Kestelier, a partner and the co-head of the specialist modeling group at Foster + Partners, says that his firm is eager to see how 3-D printing of concrete will impact project design. "The advantage of 3-D printing is that complex components don't come with an extra cost because it's just as easy to print a curved concrete wall as it is a straight one," says De Kestelier, whose firm has also been involved in a separate project with the European Space Agency to 3-D print structures on the moon using moon dust. "This technology will allow us to rethink the way we design and give us more freedom than we had before."

The new printer will be the third for Austin and Buswell. The duo developed their first 3-D concrete printer at the university with Foster + Partners, the United Kingdom-based engineering firm Buro Happold, and other industry partners. That printer used an extrusion technique similar to fused deposition modeling (FDM), depositing layers of fine-aggregate mortar to create flat, doubly curved, and hollow concrete products. The team continued working with industry partners to develop its second-generation printer, which used a modified extrusion process and a seven-axis robotic arm that gives rotational freedom to the printing nozzle.

Firms worldwide expressed interest in the technology, so researchers began searching for an industry partner with the expertise to turn the research-oriented machine into an industrial prototype. The idea was that including existing technologies for concrete-mix production and tool-path generation would further the development of the technology. "We wanted to partner with a company or consortium that was interested in radical innovation and could create their own version of our printer at their own site," Austin explains. "After some discussions, we decided that Skanska was best suited to take on the project at this stage, because they were committed to finding a good blend of partners who would tackle the challenges with enthusiasm."

The new printer is now under construction in a factory in the United Kingdom, and completion, commissioning, and testing will take place within the next 18 months. The printer will produce concrete components of various sizes and complexities, which will then be tested for strength and functionality. Once the tests are completed and the team understands the characteristics of the components better, team members will look for an opportunity to incorporate the printed elements into an actual project - possibly a building or an art installation.

"One of the obvious areas where this might be effective is in building facades because they're highly architectural," says Austin, who also helped develop the technology and materials for wet-process shotcrete repair in the late 1990s. "Concrete printing could lend itself to a facade where each panel is a little bit different, yet when they're stitched together they create a particular appearance or have some functionality that would be financially prohibitive with conventional casting, which would require a different mold for every part."

The technology may also benefit engineers and designers by allowing them to place concrete precisely where it is needed. For instance, voids can be created within the printed concrete to accommodate pipes and other mechanical systems that need to be inserted through the structure. "You can potentially optimize your cross sections of structural elements by placing concrete where you want it," Austin explains. "That would reduce weight, reduce materials, and reduce costs."

Furthermore, Skanska plans to use the technology to advance its " flying factories " concept, which involves developing mobile near-site manufacturing workshops that can move between project sites. "Three-D concrete printing, when combined with a type of mobile prefabrication center, has the potential to reduce the time needed to create complex elements of buildings from weeks to hours," said Rob Francis, Skanska's director of innovation and business improvement, in a press release issued by the firm on November 24. "We expect to achieve a level of quality and efficiency [that] has never been seen before in construction."

This article appears in Civil Engineering, The Magazine of the American Society of Civil Engineers.