It’s not every day that you look outside your window and see a 3D building being created. Earlier this month, Marisha Thakur took to Twitter to share this surprising sight, “Look ma, they are 3D printing a building outside my house.” The post went viral, with many calling it “exciting.”
The building in focus is the 1,000 square feet Halasuru Post Office, which is being built using 3D Concrete Printing Technology within 45 days, according to the Press Trust of India (PTI).
The post office in Cambridge Layout, Halasuru, is being constructed by L&T, which said the technology has been approved by Building Materials and Technology Promotion Council (BMTPC), and the structural design has been validated by IIT Madras. A fully automated 3D printer is being used on the job site in an ‘open to sky’ environment. According to L&T, the post office is Karnataka’s first public structure to be built using 3D technology, according to PTI.
Talking to The Hindu, one of the workers on site explained that the cement, sand, and a waterproof chemical are added into a churner with measured amounts of water. “The mixture then comes out in blocks, which will be laid on top of each other along with iron pillars in between for support.”
In a statement, the construction company explained that the 3D-printing process requires 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.
One of the main advantages of 3D printing a building is the reduction in cost and time. The cost of this building will be 30 to 40% lesser than regular low-cost buildings. Moreover, it can be of any shape, not limited to a square or a rectangle, S. Rajendra Kumar, Chief Post Master General, Karnataka Circle told The Hindu. The building will be completed in almost a month, Kumar added.
3D printing technology can also be used to print buildings using reusable and recyclable materials. In 2021, in collaboration with 3D-printing specialists WASP, the Italy-based studio Mario Cucinella Architects developed a low-carbon impact housing prototype called Tecla. In Malawi, 3D printing reduced construction waste almost tenfold and along with CO2 emissions by up to 70%, according to a World Bank blog post in 2022.