“This is a challenging project, preceded by rigorous sustainability testing and product development. We have learned from Karlatornet in Sweden and other tall buildings that we have delivered to, but this has posed additional demands on our laboratories in both Sweden and the USA,” says Hans Karlander, CEO and President of Thomas Concrete Group.
When the 224-meter-high building in Atlanta is completed, it will contain 350 apartments and more than 224 000 square feet of office space, making it one of the tallest in Atlanta.
In total, Thomas Concrete Group will have delivered 80 000 cubic yards of concrete to the project, where just the foundation alone required 4 300 cubic yards.
In the company’s laboratory, rigorous tests have been conducted to produce concrete with the right compressive strength, able to withstand significant stress from natural forces. The result was a low-carbon concrete mix in which only 25 percent cement is used, resulting in a GWP (Global Warming Potential) value of an impressive 181 kg/cubic meter. It has also been important to use local alternative binders, such as fly ash and slag, instead of traditional cement, as much as possible.
Thomas Concrete‘s laboratory in the USA has been leading the design work, but the company’s central laboratory in Sweden has also been involved in the project. Learnings from other tall buildings, such as the 246-meter-high Karlatornet in Gothenburg, have been valuable, and both the technical team and the engineers for the construction have been involved in the development of the advanced concrete.
“The first foundation pour was critical! The measurement of the foundation is 10,000 square feet and 11 feet thick. The pour began on a Friday evening and continued uninterrupted until what was expected to be early Sunday morning. The work had been planned for several months and was so well organized that we finished 6 hours ahead of schedule. During the entire process, a critical temperature threshold was maintained, and I am incredibly proud of our team’s collective effort to safely and efficiently deliver the foundation for this tall building,” says Chris Nowicki, Commercial Sales at Thomas Concrete in Atlanta.
The building in Atlanta is a successful example of how different stakeholders collaborate early in the construction process to reduce the environmental impact by using alternative binders to cement.
“We are inspired to take on such complex projects and to solve the high expectations from both contractors and sustainability experts in such a professional way. It shows how far the researchers in our laboratories have come and the level of knowledge within our entire team when it comes to building massively tall structures that are both strong and sustainable,” says Hans Karlander.