3D printing (3DP), referred to as additive manufacturing, is a process for making a physical object from a three-dimensional digital model by laying down many successive, thin layers of material. It brings a digital object (its CAD representation) into its physical form by adding layer by layer of materials.
Today, 3D printers can be seen building everything from homes to cars and even viable personal protective equipment (PPE), which is used by healthcare workers all over the world in the fight against COVID-19. 3D printers are incredibly flexible not only in what they can print, but also in the materials they use. Additionally, they are accurate and fast, making them a promising tool for the future. Companies the world over now employ 3D printers to create prototypes in a matter of hours instead of wasting months of time & potentially millions of dollars in research and development. The construction industry is actually using this futuristic printing method to print complete homes.
3D printing’s roots date back to the mid-1980s when stereolithography, or SLA, was conceived. SLA works as a high-powered laser and turns a liquid resin into solid material. SLA is an additive technology, which means it involves creating a product from the ground up, layer by layer. Today, SLA continues to be one of the most popular 3D printing technologies. It is interesting to note that 3D printing is generally described as any technology that creates parts in an additive way. Some other popular additive technologies include selective laser sintering (SLS), fused deposition modeling (FDM), and direct metal deposition (DMD).
Initially 3D printing was utilized for quick and accurate creation of prototype parts. As additive processes improved, however, its viable uses began to expand. Prior to the adoption of building information modeling (BIM), 3D printing was used by architectural firms to build scale models. Before long, it was deployed for more ambitious construction purposes. 3D printers have now moved out of the engineering laboratory and are slowly changing the face of construction.
There are a variety of 3D printing methods used at construction scale, the main ones being extrusion (concrete/ cement, wax, foam, polymers), powder bonding (polymer bond, reactive bond, sintering), and additive welding. Construction scale 3D printing has a wide variety of applications within the private, commercial, industrial, & public sectors.
A number of different approaches have been demonstrated to date, which include onsite and off-site fabrication of buildings and construction components using industrial robots, gantry systems, and tethered autonomous vehicles. Demonstrations of construction 3D printing technologies to date have included fabrication of housing, construction components (cladding and structural panels and columns), bridges & civil infrastructure, artificial reefs, follies, and sculptures.
Concrete 3D printing uses extremely largescale 3D printers, often measuring several meters in height and length, to extrude concrete from a nozzle. These machines generally come either as gantry or robotic arm systems.
Whatever the printer’s configuration, practically all of them continuously extrude a dough-like concrete material that is laid down in layers to create the desired building element.
Despite being called concrete 3D printing, the material used is not always concrete in the strictest definition of the word. Traditional concrete is usually not suitable for 3D printing, as it would only clog the printer nozzle and not adhere properly to the previous layers. Many of the available materials today are unique and some are patented, making successful concrete 3D printing just as much about the material as it is about the printer.
The construction industry stands to gain in many ways by adopting 3D technology. Here is a look at the benefits to be gained by employing a 3D printer in construction projects.
One of the biggest benefits 3D printers offer to construction workers is a reduction in injuries in the field. Considering that building with concrete is difficult, even dangerous, this is a welcome improvement. Not only do workers have an easier time doing their job, but employers have less worker’s compensation paperwork to wade through due to injury.
Another improvement is considerable reduction in material waste. 3D printers use the exact amount of concrete needed for the wall, floor, or whatever needs to be built. Builders and contractors need not order in bulk because they know exactly how much material they need. Not only is this a more sustainable, environment-friendly way to build, but it also results in reduced costs for the contractor and eliminates pile up of concrete waste.
This is where concrete 3D printing truly offers a clear advantage over traditional construction methods. Where a project may sometimes take weeks—or months—to complete, 3D printers can often finish the job in a matter of hours or days. This allows contractors to move on to other projects sooner and more orders filled means more revenue for the contractor.
Besides low costs, reduced labor, and faster construction, another upside of 3D printing technology is that it offers unique building opportunities that would otherwise be expensive with traditional building methods. It leverages innovation and creativity by effortlessly allowing the creation of complex shapes and forms. For instance, a 3D printer can produce an intricately curved wall as easily as it creates a straight one.
Using a 3D printer also allows construction companies to work in markets that might have been otherwise inaccessible. For new construction companies in particular, having a 3D printer could set them apart from companies that have been around for a few decades & are resistant to change. Similarly, traditional and established construction companies could utilize 3D printers to make sure they remain relevant in the market. Essentially, 3D printers can be used both as a means to enter a new market and to give an established company competitive edge.
Overall, using 3D printers costs less than traditional construction techniques & processes. With reduction in injuries, time, and material cost, companies will see a dramatic increase in their profits. A 3D-printed house requires a handful of laborers on-site as much of the construction is automated. For instance, constructing a 2,000-square-foot house would require less than five people, replacing the over 20 manual laborers needed in traditional construction.
While testing concrete during the early stages of construction will continue to be necessary, 3D printers have been found to contribute to the durability of structural elements. This is due in part to how the materials are made the manner in which they are assembled. More durable buildings mean fewer repairs need to be made, so construction companies can focus their efforts elsewhere to drive profit. For clients, too, preferences certainly tilt toward a building that will last longer.
3D printing is emerging as an energy-efficient technology that can provide environmental efficiencies in terms of the manufacturing process, utilizing up to 90% of standard materials and, therefore, creating less waste. Also, its lighter and stronger design entails a reduced carbon footprint compared with traditionally manufactured products. More important, 3D printing is showing great promise in terms of realizing a local manufacturing model, whereby products are produced on demand in the place where they are needed— eliminating huge inventories and unsustainable logistics for shipping high volumes of products around the world. Recycled products can be used to produce the construction materials used in 3D printers.
Despite the benefits and potential that 3D printing offers in the construction sector, there are a number of factors that may hinder the technology from becoming mainstream. Let us explore a few of these challenges.
Perhaps the biggest challenge to the widespread adoption of 3D printing technology on construction sites is the high cost of purchasing or renting the equipment and the logistics involved in getting the large 3D printers to the work site. 3D printers are costly, & that upfront purchase cost doesn’t include materials or maintenance. Right now, it is difficult for construction professionals to justify 3D printing’s prohibitive cost with the technology’s benefits.
Adopting 3D printing technology requires skilled labor. On the one hand, high technical expertise is required to operate & maintain printers, which requires trained or upskilled labor. On the other hand, in developing countries, existing labor will face unemployment as the 3D printer will do most of the work.
Weather already has the potential to slow construction progress, but issues with Mother Nature may be amplified with 3D printing. The weather, environmental factors, and more are all conditions that could make 3D printing in commercial construction more of a bust than a boom. Furthermore, quality control in construction is already a tricky matter. If not constantly monitored by humans, quality in 3D printing could suffer, and the products could end up being an expensive mess.
One drawback that might not immediately come to mind is the regulation of 3D printing. While regulation in 3D printing has made news recently, it has yet to fully impact the construction industry. Using printers rather than humans to perform certain construction tasks may become a liability in future. Currently, there’s much uncertainty around this aspect of 3D printing in construction. Until laws and regulations are clearly defined, it is unlikely that 3D printing will make strides in the construction sector.
Getting printers for large in situ components to and from the site is a challenge. Current 3D printing technology cannot build tall structures. Printing cantilever parts poses a challenge for and is a limitation of this technology.
Although 3D printing technology is still evolving, researchers believe it has the potential to pave the way for more economical, sustainable, ecofriendly, and faster means of construction.
3D printing is expected to go mainstream over the next 10 years, especially in countries facing labor shortages. It is estimated that enhancing 3D printing technologies will play a role in saving construction costs by 50% to 70%, labor costs by 50% to 80%, and reducing construction waste by up to 60%.
Research is being conducted globally to optimize the capacity, the bond strength between the subsequent layer, and the use of reinforcement in 3D printed concrete. In addition, efforts are being made to develop standards/specifications of 3D printed concrete so that code-based design of 3D printed concrete structures or structural components can be initiated to take the technology forward. Further, the use of reinforcements in the 3D printable concrete is expected to open up exciting new avenues.
In its current state, the largest immediate impact that 3D printing has is in producing models from drawings. A 3D model communicates an idea more easily than drawings. Cyient helps customers reduce costs and create more value by providing specialized 3D modeling services. We provide end-to-end solutions and expertise in both polymer and metal 3D printing services. Cyient improves efficiency through digital solutions, such as BIM, 3D modeling, AR/VR, and image analytics.
Cyient (Estd: 1991, NSE: CYIENT) is a leading global engineering and technology solutions company. We are a Design, Build, and Maintain partner for leading organizations worldwide. We leverage digital technologies, advanced analytics capabilities, and our domain knowledge and technical expertise, to solve complex business problems.
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