Lotte Engineering & Construction (Lotte E&C) announced on March 17 that it successfully installed 46,000m3 of eco-friendly concrete using slag at the Lotte Mall in Hanoi, which is under construction in Vietnam.
Eco-friendly concrete is a technology that reduces the use of cement, which is a common concrete binding material, to 50%, increases fly ash and furnace slag powder by 20 and 30%, respectively, reducing carbon dioxide generation and improving durability of buildings.
In Hanoi, Vietnam, a ready-mixed concrete mix that usually uses only 15% fly ash in addition to cement was used as a concrete combination, but slag production became possible after a steel factory was established in Hanoi in 2019.
Lotte E&C conducted a joint study with Vietnam Institute for Building Science and Technology (IBST), a construction technology research institute affiliated with Vietnam's Ministry of Construction, to develop a concrete mix using furnace slag fine powder.
As a result, the company developed concrete that lowered the hydration heat generated in the process of concrete hardening by 10°C compared to the existing combination, and improved the long-term strength of concrete after 90 days by 20%.
This technology reduces the use of cement that emits large amounts of carbon dioxide, a greenhouse gas, in the manufacturing process.
In fact, the technology has been applied to Lotte Mall Hanoi to reduce the generation of about 4,920 tons of carbon dioxide.
"This method of eco-friendly concrete was already applied in Korea, but there were not many slag production in Vietnam, so only a small amount of fly ash was used," said an official at Lotte E&C Technology Research Institute. "We were able to apply it to the Hanoi site for the first time."
