Nestled in the heart of Bangkok’s Chinatown, the Ong Ang Canal served as a vital trade artery in the 18th century. Over time, it became heavily polluted, and even earned a reputation as the city’s dirtiest canal.
Last month, as part of a broader government effort to revitalize the canal, Siam Cement Group (SCG), Thailand’s oldest cement firm, unveiled the country’s first 3D-printed pedestrian bridge across its waters.
The bridge is part of SCG’s drive to bring new construction materials to Southeast Asia, Surachai Nimlaor, who helms its operations in cement and green solutions, tells Fortune in a Jan. 20 interview.
The company first started applying 3D printing tech to construction in the early 2020s, including the 2023 construction of the world’s first 3D printed medical center in Saraburi, Thailand.
“When we use 3D printing, we can shorten construction time and create buildings with unique shapes that conventional builders may not be able to achieve,” says Nimlaor.
The process involves creating a digital model, slicing it for the 3D printer, and then allowing the printer’s robotic arms to set down concrete, layer-by-layer, to form structures. By removing the need for traditional molds or formwork, it enables freeform architecture which includes sculptural curves and undulating walls. SCG’s 3D printed medical center, for instance, has fluid facades that would be difficult to execute with conventional cast concrete.
Courtesy of Siam Cement Group
This technology could be especially valuable for Thailand, where an aging population and a workforce wary of construction jobs is shrinking the sector’s pool of available workers. Nimlaor explains that the industry has been forced to turn to foreign workers from neighboring countries like Cambodia and Myanmar. (According to 2025 data from Cambodia’s Ministry of Labour and Vocational Training, there are over 1.2 million Cambodian workers in Thailand, many of whom are employed in construction.)
Still, 3D printed buildings are often only one or two storeys tall, Nimlaor admits, as taller buildings introduce “material constraints around structural loads and stability.”
Thailand’s first cement firm
SCG was founded in 1913 to build Bangkok’s first cement plant, under the orders of then-King Rama VI. In the century that followed, the company expanded to focus on three core businesses: cement and building materials, chemicals, and packaging.
Today, SCG is Thailand’s largest building materials company, with a 2024 revenue of $14.5 billion. It ranks No. 21 in Fortune’s Southeast Asia 500 list, which sorts the region’s largest companies by revenue. SCG has also expanded to other parts of Southeast Asia, including packaging businesses in Malaysia and a petrochemical plant in Vietnam.
Greening the construction industry
Beyond 3D printing, SCG is also developing low-carbon cement, tackling an industry that accounts for roughly 8% of global carbon emissions, according to the World Economic Forum.
SCG is trying to formulate cement produced using biomass, like wood. This cuts the carbon emissions from the production process by as much as 20% per ton, Nimlaor claims. SCG now exports its low-carbon cement to the U.S. and Australia, where developers now prefer materials that meet ESG standards.
“ESG has become a very strong driver in the global market,” he explains. “Many companies now have clear carbon-reduction targets and sustainability commitments.”
SCG hopes to launch the third-generation of its low-carbon cement, which would cut carbon emissions from production by up to 40%, but Nimlaor has hopes that they can eventually cut emissions by up to 90%.
Looking forward, SCG hopes to continue pushing the boundaries in creating greener construction materials. “Sustainability and business growth must go together,” he concludes.
