Today, the construction industry has been moving to 3D concrete printing. It has been identified as a potential game changer for the construction industry. 3D concrete mix design requires paradoxical combination of concrete properties to print successfully. It is said that 3D concrete printing will also change the dynamics and offerings of the affordable and mass housing industry.
Here, MV Satish, Whole‐time Director & Senior Executive VP, Larsen & Toubro, tells us more. Excerpts from an interview:
DQ: What prompted L&T to take this innovation?
MV Satish: One of the programs that the Centre is driving is that of ‘Housing for All’ to meet the burgeoning urbanization requirements that will involve creating about 60 million new houses.
Realizing the huge opportunity, L&T Construction added muscle and intent to its effort to seek and leverage the latest technologies and adopt innovative construction methods to build to speed and scale.
During this process, 3D concrete printing was identified as a potential game changer for the construction industry. As the technology was then at a nascent stage, a dedicated in-house R&D team was tasked to study the feasibility of adopting 3D concrete printing by evaluating various aspects like the right concrete mix, the most effective process and work methodologies, and the like.
DQ: 3D is an old technology, but the usage of its technology in construction is new or maybe, the first time has been used by L&T. How is it a different experience in the construction?
MV Satish: 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 and 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 and processes for best results.
DQ: What were the challenges in its usage in construction?
MV Satish: 3D concrete mix design requires paradoxical combination of concrete properties to print 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 printhead to accommodate the revised printing methodologies.
DQ: What are the major benefits?
MV Satish: The absence of conventional formwork systemsand high–design flexibility offered by 3D printing technology gives architects and design engineers the license to ‘imagineer’.
They can for possibilities beyond the constraints ofconventional formwork and 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.
DQ: Have you started adopting commercially? If yes,which is the first project? If not, from when they will adopt?
MV Satish: 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 the3D printed buildings will be used for such testing and validation.
DQ: How do you see the future of 3D printing in the sector/industry?
MV Satish: 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 designs. Architects will begin to play a more defining role to build fluid and building structuresthat can take aesthetics and convenience to the next level. Made-to-order houses are not too far away!