There is a lot of work happening around 3D printing of concrete across the world, with as many as 65 companies and organisations developing construction-based 3D printing, according to a study by US-headquartered Boston Consulting Group.
The concrete dispensing printing systems being developed are generally based on one of two processes, either extrusion using robotics or binder-based using gantry systems. As with all 3D printing technologies and their application across various sectors, the value add of 3D printing lies primarily in the possibility to create complex shapes – complexity of design comes free.
There is a lot of focus on robotic 3D printing of concrete structures due to the technology’s ability to generate freeform structures that would be difficult or impossible to make using traditional methods. To tackle the issue of strength, there is ongoing collaboration between industry and academia to allow for the incorporation of reinforcements without compromising on the design freedom that 3D printing enables.
At present, 3D printing of concrete is suitable for architecturally complex designs that are geared more towards monumental and sculptural structures than everyday buildings, although foot bridges, building facades and the use of 3D printed moulds are some of the applications that are providing immediate value to contractors.
However, the technology is advancing, and investment in materials being used for 3D printing construction is growing. Over the next 5 to 10 years you will see a convergence of robotics and 3D printing with conventional and existing building processes, as we have seen across many sectors.
|UAE-based Immensa Technology Labs, in collaboration with BigRep and Consolidated Contracting Company, printed the formwork at Immensa’s facility in Dubai to fabricate an intricate, smart concrete wall that would not have been possible to make using traditional construction methods|
Today we are still at the first generation of 3D concrete printers, but we can easily see robots and robotic processes at construction sites by 2025 and in turn being an integral part of the construction process. US space agency NASA is making significant investment in the development of 3D printers for building functional structures, with a view to construction in outer space.
One key area in which 3D printing will have a big impact in the short-to-medium term in the construction industry is the methodology and process of building. As people advocate 3D printing of concrete, you will find an increasing number of 3D designs and drawings being created. As 3D data is created, the traditional process of construction management will be disrupted and 3D printing technology will deeply influence architectural design and construction methods in the future.
We expect to see the combination of building information modelling (BIM) and virtual reality completely change the way traditional building is managed, with approvals done in 3D drawings, and inspections and approvals obtained based on 3D evidence. This is a space to be watched.
We expect the biggest impact 3D printing of concrete will have is not from the actual physical extrusion of concrete via a machine-controlled tool, but from the entire workflow process – a disruptive change to the entire value chain and methodology of how construction is done.
A lot of building designs that would have been deemed impractical in the past are now deemed possible with 3D printing. There is an increasing fusion of 3D printing with traditional construction methods such as casting that has enabled the fabrication of concrete structures that would have been impossible with each of the technologies alone. This trend of combining 3D printing with the best of other technologies is likely to become mainstream in the future.
The main challenges now are the costs associated with using 3D printing and the strength of the resulting concrete structures. Compared with traditional construction methods, 3D printing can seem expensive, especially when the resulting structure does not exhibit strengths comparable with that obtained from traditional methods. However, research is ongoing to address these issues. For example, polypropylene fibres have been found to significantly improve the strength of 3D-printed concrete, and hybrid methods of construction, which involve the placement of reinforcing iron rods at critical sections, are being explored. As for cost, once the strength issue is fixed, the benefits of design freedom and rapid construction are likely to outweigh the capital costs of the 3D equipment.
Regulation is also a huge challenge as this requires governing bodies to qualify and standardise 3D printing to incorporate it into building codes. Without this, neither the technology nor the materials used for 3D-printed concrete will be able to enter the commercialisation stage.
There is also still more research and development work to take place between educational institutions and private companies. The projects being committed to in places such as Dubai and Riyadh, for example, are provide a massive amount of learning. These projects are not viable if evaluated solely from a commercial or technical perspective, but are a necessity if 3D printing is to progress in the construction sector. The Dubai government’s push into this area can only expedite development.
Fahmi al-Shawwa (left) is founder and CEO of Immensa Technology Labs; Edem Dugbenoo (right) is an engineer at the Dubai-based additive manufacturing company