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3D Printing to Usher Construction to the Next Level

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Excerpts from an interaction with M V Satish, Whole‐time Director & Senior Executive Vice President (Buildings), L&T. His experience is rich and varied having worked across domains like hardcore Construction, Business Development, Contracts Management and Property Development.

Usage of 3Dprinting technology in construction is new or it maybe the first time that it is being used by a construction company. How is it a different experience in construction?

3D printing is predominantly used in various manufacturing industries to print rapid prototypes, complex shapes and small batch production using special polymers, metal alloys, etc. 3D printing with concrete is, however, a completely different ball game that requires comprehensive knowledge and control of the 3Ms (Material, Methodology and Methods) for successful large-scale & speedy operations and the perfect synergy of the 3Ms and their seamless integration to the system.

In manufacturing industries, 3D printing is executed in a controlled environment, where factors like ambient temperature, moisture, humidity, dust, etc., are tightly controlled. As most construction projects are executed in an open to sky environment, these variables are less in control that require setting up of appropriate systems & processes for best results.

What are the challenges in its usage in construction?

3D concrete mix design requires paradoxical combination of concrete properties toprint successfully. The properties of 3D printable concrete are not straightforward as it involves various mandatories like maintaining sufficient ‘flowability’ till the concrete reaches the printer head. Once the concrete layer is printed, the structure must immediately gain sufficient hardness to retain its intended shape. There is the requirement to maintain green concrete status to ensure bonding between the layers and yet gain sufficient hardening to take the load of subsequent layers. After various lab experiments and field trials, a perfect concrete mix design was arrived at that adequately met all the above properties.

To optimize the cost of constructing mass housing, it was strategically decided to use regular, locally available construction materials for the mix design to produce at job sites, unlike the present industry practice of buying factory produced pre-packed mortar.

Integration of horizontal and vertical reinforcement during the printing process has been another challenge for which certain ingenious methodologies have been devised to embed the reinforcement and suitably modify the print head to accommodate the revised printing methodologies.

What are the major benefits of this technology?

The absence of conventional formwork systems and high design flexibility offered by 3D printing technology gives architects and design engineers the license to ‘imagineer’.They provide possibilities beyond the constraints of conventional formwork & execution methods. Innovative and fluid construction designs can be explored to enhance aesthetics, improve convenience, and optimize cost. Certainly, fully automated construction will accelerate the pace of construction and ensure high build quality and safety.

What are your thoughts on commercial viability of the technology and future prospects for the same?

With the successful 3D printing of a G+1 building in accordance with the Indian CODAL provisions for such structures, L&T Construction has proved that the organization possesses the requisite expertise to leverage this futuristic technology.

However, being a new technology involving a fully automated construction methodology, there are still a few design validation processes to be completed, before taking to market that are being currently addressed through various Indian statutory bodies, research institutions, and the like. Both the 3D printed buildings will be used for such testing and validation.

How do you see the future of 3D printing in the sector?

3D concrete printing will completely change the dynamics and offerings of the affordable and mass housing industry. It will usher in a significant upward shift in safety, speed, scale, and superior design. Architects will begin to play a more defining role to build fluid building structures that can take aesthetics and convenience to the next level. Made-to-order houses are not too far away!