How India’s first 3D

Oct 23, 2023

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News of India’s first 3D-printed post office building went viral in April when a wonder-struck resident at Bengaluru’s Cambridge Layout locality tweeted a video of a robotic arm at work, its nozzle intricately depositing layer upon layer of concrete to build the walls of the structure. Last week, the Ulsoor Bazaar Post Office—completed in 43 days—was formally inaugurated, making it one of the first public buildings in the country to be literally printed out from a 3D design.

The highlight of the post-office is its design. With a curved exterior, the structure measuring 1,021 sq. feet of built-up area somewhat resembles the shape of a bell. Normally, using conventional methods of construction, it would have taken six months to complete the building. In fact, 3D printing the post office was originally scheduled for 45 days but completed with two days to spare. The overall cost was under Rs 25 lakh.

Speed and flexibility in design are the two big advantages that 3D printing technology offers, said Prof. Manu Santhanam, of the department of civil engineering at the Indian Institute of Technology (IIT) Madras, at the inauguration. “We can now produce shapes that were inconceivable in the past. So, we are playing at the edge of what construction can actually undertake in the future,” he said. While L&T Construction executed the project, IIT Madras validated the structural design.

The Ulsoor Bazaar Post Office has no vertical pillars. While some of the walls were printed solid, in other sections they were laid out with cavities into which specially-made concrete and steel were set in for reinforcement. As Santhanam explained to INDIA TODAY, regular concrete is usually made fluid so as to fill up the design mould and harden over time. However, the concrete used for 3D printing has to take shape as soon as it comes out of the nozzle. “So, it maintains that shape, and when the next layer is placed on top, the bottom layer should not deform,” he said.

The process, according to L&T, required a “delicate balance of concrete properties, including flowability, quick hardening for load-bearing capacity, green concrete status for inter-layer bonding, and sufficient strength to ensure successful printing”.

Currently, L&T is working on a 3D printed building complex in Chandigarh for the Border Roads Organisation besides a villa project at Bengaluru and buildings for a factory, the company said in a release in April. The firm’s primary focus, it said, includes affordable housing up to ground-plus-floors, villas, military barracks, single-floor schools, post offices, and factories.

While 3D printing in the manufacturing and medical sectors has had a headstart, its applications in the construction sector were mostly at a lab scale till a decade ago when global companies began developing large systems to handle the printing.

In 2020, IIT Madras built a one-bedroom house—touted as India’s first 3D-printed house—on its campus along with Tvasta, a start-up that had been incubated at the institute.

Currently, there are several start-ups in India developing 3D printing technologies, said Santhanam. He explained that 3D printing can be a viable option in certain scenarios, such as constructing row-houses or community development projects in peri-urban areas. “If you are going to be using that same printer to print multiple houses in one location, let’s say 10-20 houses, then you definitely have a cost advantage and design flexibility,” he said.

By flexibility, Santhanam was referring to how, even while designing row houses, each unit can be customised to a certain extent. However, for mass housing projects in urban areas, existing technologies such as pre-cast concrete can be quicker and more efficient, he pointed out.

Globally, researchers are working on some key aspects of 3D printing—integrating reinforcements into the design, reducing the overall cost of raw materials and increasing sustainability. “Many of the concrete mixes used for 3D printing are rich in cement. Cutting down cement in concrete is a big challenge that most of us are engaged in,” said Santhanam. Standards will also have to evolve for 3D printing construction to become commercial, he added. “There are a lot of groups across the country...several IITs and others...working together. We are part of a Bureau of Indian Standards (BIS) committee and intend to bring out a handbook that talks about such design ideas.”

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