When it comes to innovation and adapting to new technology, Larsen & Toubro continues to push the boundaries. Leveraging the ever-evolving technology, the giant has now constructed India’s first 2800 mm-high residential building using 3D Printing.
In doing so, L&T has also set a world record ~ for the first time ever, concrete mixed with crushed sand (more than 4.75 mm size) has been used in a 3D printer. Experiments are being done worldwide to study the feasibility of using 3D printing technology to construct buildings. As India’s largest construction company, L&T stays abreast of the latest technological developments.
The 240 sq ft built-up single-storey building has been constructed by L&T’s Building & Factories business at its facility at Kanchipuram in Tamil Nadu.
The concept was developed in-house by Concrete Management Department in association with M/S COBOD, makers of gantry-type 3D printers. While drawing up its strategic road map, B&F identified 3D concrete printing as a technology disruptor with the potential to radically redefine construction methodology and industry dynamics. A dedicated team commenced research on various aspects of 3D concrete printing, including developing the right-mix design, identifying the right printer, execution methodology, etc.
Deciding the perfect concrete mix posed several challenges. It had to be workable to get pumped into the hopper and extruded through the nozzle. It had to immediately retain its intended shape as there were no supporting formwork structures. And it had to harden as quickly as possible to bear the weight of subsequent layers being printed on top.
To make it economical, the team developed the concrete mix using construction materials which are normally used for concretes and thereby avoided prepacked materials. This called for testing with various combinations of fines, fibres, plasticisers, retarders, accelerators, etc. to ensure the right workability, viscosity and concrete setting time.
After various lab experiments, a perfect mix, meeting the above requirements, was developed by the Concrete Management team. Next, an extensive market research revealed that the 3D printer most suitable for the purpose is the one manufactured by COBOD International A/S of Denmark.The in-house mix was tested on a small scale at COBOD’s warehouse in Dubai and was found suitable. Subsequently, L&T imported COBOD’s Version 1 Gantry type printer and commissioned at the Kanchipuram facility.
It was for reason that senior L&T officials were overjoyed by the remarkable feat. Mr M V Satish, Whole-Time Director and Senior Executive Vice President (Buildings, Minerals & Metals), Mr S Kanappan, Head & Chief Executive (L&T GEO), and Mr P R Surendhrababu, Vice President & Head – Digital Engineering, rushed to the 3D printed building site.
