At Concrete 2021 in September this year you can expect to see presentations from keynote speakers with legendary expertise. One such speaker will be Professor Richard Buswell of the School of Architecture, Building and Civil Engineering at Loughborough University (LU) in the UK. He is recognised internationally as a pioneer of 3D concrete printing (3DCP) and is a core member of the international RILEM Technical Committee on Digital Fabrication of Cement-based Materials.
Professor Buswell has over 24 years’ experience in building energy research and more than 17 years in large-scale additive manufacturing for construction. He was the Principal Investigator on a number of large, multi-disciplinary projects including the Freeform Construction: Mega-scale Additive Manufacturing for Construction project at LU that coined the name ‘3D Concrete Printing’ and delivered the world-first technology. The project ran from 2006 to 2011 and at the time of the LU project, there were only two other organisations globally that were undertaking investigative work in applying narrative approaches to construction manufacturing.
In the US, a technology was being developed for the automation of deposition of material for the on-site manufacture of walls for buildings. And in Italy a large-scale 3D printing method was being developed using a sand as the build material, solidifying it by selectively squirting a binder onto the surface to form solid objects, according to Dr Buswell.
“Our approach was not to compete with these methods, rather we thought we saw a third way the technology could be deployed and that is in the offsite manufacture of concrete components,” he explained. “We then focused on developing a process that was adapted to that challenge.”
Of course the project was a “terrific success” in demonstrating the viability of using additive manufacturing methods and concrete as a building material. Professor Buswell said there is a great deal of interest around the potential to manufacture bespoke and nonstandard components where traditionally the complexity of the parts would be too expensive if not impossible to manufacture with conventional techniques such as moulding. Architecture in particular was very interested in what the technology would mean for the design and fabrication of buildings and the built environment and we’ve seen many applications for 3DCP from street furniture to houses manufactured in recent years.
Two papers of interest from Professor Buswell’s 2012 research into 3DCP fresh properties and hardened properties are to be found at https://bit.ly/3j9Uedn and https://bit.ly/2O1Gcz1 respectively.
Fast-forward to 2021, there are now many research-based and commercial 3DCP processes. In fact, there are around 35 commercial organisations claiming to o¬ffer some form of 3DCP around the world with half specialising in delivering on-site construction while the other half is split across a range of di¬fferent products in the offsite manufacturing field, according to Professor Buswell.
His current research involves understanding how reinforcement behaves in the 3DCP material and how reinforcement can be incorporated alongside a 3DCP material. His team is questioning how this a¬ffects the performance of components and how then to design for the manufacturing constraints.
“If we are able to understand how we can predict the performance of the reinforced, printed material then our partners and the wider industry will be empowered to design for 3D concrete composite components and will open pathways to many new applications”, Professor Buswell explained.
The other aspect of Professor Buswell’s current research is the issue of manufacturing tolerances. “Currently 3DCP can deliver freedom of form, but creating parts with greater accuracy will open up more applications. The aim of the work is to achieve sub-millimetre accuracy” through the application of secondary processes to achieve high quality surface finishes and precise interface sections.
“Combining the ability for accuracy in components with that of being able to reinforce them will open up opportunities and applications for 3D concrete printing far beyond that of architectural objects and into the delivery of future buildings and infrastructure,” Professor Buswell said.
The advantages of supplying components that are manufactured in a fully digital process have many benefits and ‘just-in-time production’ will become more viable.
“You’ll be able to take your bespoke design idea, through design for manufacture based software to deliver materials costs and schedule for manufacture in a fraction of traditional lead in times.” he explained.
“For some bespoke parts the technology can reduce this from weeks to hours.” Additionally manufacture and delivery can be scheduled to suit site conditions which minimises storage time and the potential for damage.
“And because components can be scheduled to be manufactured at the last minute and that this is all done from digital information, it allows for modification of the designs of those components until the last minute meaning that parts can be adapted to fit exactly the pre-existing conditions on-site saving rework and speeding up installation times.”
Professor Buswell believes this will become increasingly important as the industry starts to renovate and adapt existing buildings more rather than creating new builds.
Make sure you don’t miss Richard Buswell’s keynote presentation at Concrete 2021!