3D printing with a concrete-like material is one of the technologies that has made personalization possible. Because of its ability to produce complicated shapes, 3D concrete printing can be a long-term solution. According to recent studies, new computational technologies and 3D printers have the ability to alter how we construct our surroundings. This technology enables the fabrication of and testing with numerous devices required to assess the structure in a timely and cost-effective manner.

Even though this new technology offers numerous advantages and benefits, we still have some worries, because the technology still has several limitations. The technology has also showed promise in a variety of fields, but 3D printing in the construction business is still in its early stages. The impact of 3D printing on the construction sector should not be underestimated, as it has the potential to reduce a variety of determining elements such as the construction process, material costs, and the overall project timeline.

3D Printing Technology: Additive Manufacturing

This century has become prominent with two main concepts in architecture: the first is sustainability in architecture, which has been seeking a lower environmental footprint in the ecosystem, and the second is digital technologies, which drive a novel approach in all kinds of man-made products, including architecture. Computer-aided design (CAD) has evolved from a medium of representation to a medium of design and manufacturing in architecture.

3D printing is a technique for creating actual objects by layering materials based on a digital model. All 3D printing methods necessitate the collaboration of software, hardware, and materials. Charles W. created the first 3D printer in 1983, and 3D printing has become one of the fastest developing technologies in recent decades. It was an extremely sophisticated and expensive technology in its early days. Over time, 3D printing became more prevalent in everyday life, and printers were increasingly used in industrial settings.

Many people will refer to 3D printing as ‘additive manufacturing,’ especially when it is used in a factory setting, and many others will use both terms interchangeably. 3D printing technology can be used to make everything from prototypes and simple parts to highly complex final items like aeroplane parts, life-saving medical implants, automobiles, and even artificial organs employing layers of human cells as the technology advances.

As previously said, there are a variety of 3D printing processes that process various materials in different ways to produce the final thing. Industrial prototyping and production applications today commonly use functional plastics, metals, ceramics, and sand. The many types of 3D printers use different technologies to process various materials in different ways. Selective laser sintering (SLS) is a 3D printing technology in which a laser is used to fuse powder particles together to create an object. The materials utilised in SLS technique are typically strong and flexible. Nylon or polystyrene are the most common.

3D Concrete Printing

Cementitious 3D construction printing (3DCP), often known as 3D concrete printing, is a type of additive manufacturing that allows for the fabrication of wholly new geometries not previously feasible with standard concrete formwork. Three phases are involved in 3D printing a thing with concrete: data preparation, concrete mix preparation, and object printing.

They developed the spatial model of the object to be printed in CAD format during the data preparation stage. Using one of the slicing software’s, the item is then split into layers. The software generates a layer-by-layer concrete-laying plan for the 3D printer. The next step is to prepare the concrete mix and regulate the concrete feeding to the 3D printer. The combination is mechanised and continually feeds into the printer.

The concrete mixture is squeezed out of the printer through the nozzle and arranged in layers in the third stage. The concrete travels through the printer’s nozzle on a predetermined path to the 3D printer, as controlled by the user. This approach is planned in such a way that the printer lays down the concrete layer by layer, resulting in an actual three-dimensional object. In this step of the printing, the concrete’s workability is critical. Both the extrudability and buildability of concrete are determined by its effectiveness.

Concrete 3D Printer

Concrete 3D printing has numerous applications in the construction business. Printing elements in a factory and then transporting and assembling them on construction sites is one approach. Another alternative is to set up the printer on a building site and print the structure in pieces on the site before putting it together, or to print the structure directly on site.

In the printing industry, there are two types of printers now in use. A framed printer is the first type. Because these printers are difficult to move and build, they would only be appropriate for factories. This printer’s disadvantage is that the printer’s frame must be larger than the structure itself. The printer’s wider chassis makes it more expensive to move and assemble.

A non-framed concrete printer is the second type of printer. It’s a vehicle-mounted robotic printing arm. Unlike framed printers, this type of printer may be readily transportable and does not require flat ground. CyBe constructions in the Netherlands use this type of non-framed 3D printer.

3D Printing Optimized Concrete Structure

3D concrete printing can be utilised to lessen the industry’s environmental imprint in addition to its economic and architectural benefits. Because of the higher level of control provided by 3DCP, an advanced computational approach can be used to minimise the density of the structure by forming a lattice structure. These optimised structures not only lower total weight, but they also improve resource use. In addition, structural components such as rebar and pre-stressing cable can be incorporated to generate structural concrete. One recent example is a 3D printed pedestrian bridge, where the printed structure was post-tensioned after the individual 3D printed parts were assembled.

It’s worth noting that traditional optimization software only considers isotropic material properties during analysis; however, in 3D printing projects, the part design must be finalised while taking into account the properties and limitations of a 3D concrete printer as well as the material properties.

Limitations of 3D Concrete Printing

Concrete printing and other AM technologies still face a slew of obstacles to overcome before becoming widely adopted. This comprises precise material distribution and positioning, as well as control and monitoring of the material’s phase transition from fresh to hardened state.

In addition, concrete stacking may result in the production of “cold joints,” which refer to poor connection between layers, lowering structural strength. The use of steel or fibre reinforcement, as well as the product’s surface polish, are also important considerations. Furthermore, established regulations, benchmarks, and testing procedures to certify the safe and long-term use of concrete printing as a construction process have yet to be devised. In order to successfully 3D print concrete structures, the following key qualities of concrete must be improved:

• Extrudability
• Flowability.
• Buildability
• Open time and 
• Layer to layer contact

Future of 3D Printing in Construction

Although 3D printing technology (Stereo Lithography, Fusion Deposition Modelling) has been around since the early 1980s, it has been reluctant to catch on. There are many perspectives on where the technology might go, but it will become more cost efficient in a variety of industries, making research and mass customisation in architecture more possible. Although 3D printing is still in its infancy across all industries, the technology’s prospective benefits appear to be propelling it forward. Some predict that 3D printers would mostly be used to manufacture building components and panels in factories or on-site, while others see 3D printing as a transformative technology that will alter the construction sector.

Applying Three-Dimensional Concrete Wall Printing Technology in India

There are various disadvantages to India’s conventional construction method. The long time frame, big number of utilised labour, high percentage of error, and long-distance transportation all demonstrate this. All of these difficulties have a negative influence on the environment and raise development costs. The emerging new technique of three-dimensional printing can effectively overcome such drawbacks.

As a result, for the use of 3DP technology in India and its impact on the Indian market, a SWOT analysis will be utilised to identify the problems and obstacles of applying this technology to the Indian domestic market.

Possibilities

According to discussions, construction time efficiency may be a crucial role in the introduction of this technology in India, but the type and scale of the structure are also important factors to consider.

As a result, it is possible to argue that 3DP technology will be successful in both mass manufacturing projects and massive buildings with restricted floors. Has the potential for speedy production and high quality, which could compensate for the current low quality of work among working people. Furthermore, the adoption of this technology will allow certified architects to reclaim control, resulting in improved internal environmental quality and energy performance in the construction industry across the country. Furthermore, modifying India’s current building standards may increase architectural identity and strengthen architects’ final responsibilities in the construction business.

Challenges

When comparing the cost of bricks (used for ordinary wall construction) to the cost of reinforced concrete (which should be utilised for 3DP), the projected hurdles to the use of this technology are linked with cost. More obstacles include a lack of practical knowledge, a lack of scientific information, and industry/society rejection of norm-changing approaches, as well as a lack of stakeholder interest, a skilled workforce, and the cost of importing. Another factor to consider is modification restrictions, as working with established models limits design flexibility.

It’s also unable to receive change orders during construction, thus design changes are out of the question. Modifications are also not possible during operation. Other factors to consider include the high costs of durability and maintenance operations. Furthermore, the primary source of worry is that 3DP technology is imported rather than developed locally, resulting in significant cost increases.

S.W.O.T Analysis

As a result, a SWOT analysis is created to identify external and internal factors that influence the broad adoption of this technology in the context of the country. The former refers to the technology’s strengths and weaknesses, whereas the latter refers to external elements that could be viewed as opportunities or dangers for using this technology in the local construction market.

As a result, 3D printing technology has given industry new opportunities, such as speedier product design, customization, cost reduction, tangible product testing, and more. 3D printing, on the other hand, has a downside and isn’t always the best option for product creation. 3D printers have the potential to be dangerous and wasteful. In addition, their economic, political, sociological, and environmental consequences have not been thoroughly investigated.

Conclusion

The rapid advancement of 3D printing technology has changed people’s minds about using concrete as a 3D printable material on its own. Construction is one of the most labour-intensive businesses, with low productivity and little technological use. 3DP, like robots and other automation technologies, is gaining traction in the construction industry. 

According to the literature, 3DCP greatly reduces the number of labours in the construction process and might save 50–80% on labour expenditures. As a result, the 3DCP is projected to solve the labour shortage problem, particularly in nations where construction is primarily reliant on migrant workers. Jobs lost as a result of the usage of 3DCP, on the other side, may be negative to countries where construction is a key workforce. 

This innovation have the potential to transform the construction industry’s future. The truth is that none of the 3D construction printing projects that have been completed so far have been competitive. There may have been some cost savings in labour and materials, but it was not competitive with standard construction methods. Many companies are clearly interested in 3D concrete printing technology, but there is still a lot to learn about it in the near future.

Much more research is needed on still-unsolved issues such as structural and mechanical stability, material life, and toxic effects of materials, to name a few. The life cycle performance of printed buildings/building components is currently unknown, especially because 3D printing in the construction industry is still in its infancy. It is plausible to argue that by focusing on these issues, 3D printing will soon attain its full potential in the building business.