MBUSI, Mercedes-Benz’s North American manufacturing facility, is more than just a world-class automotive factory. It’s a marvel of concrete engineering.
During the most recent expansion of the plant, CEMEX USA supplied more than 80,000 cubic yards of custom-designed concrete, tailored to meet the specific structural needs of this massive and challenging project.
CEMEX was brought on as the concrete supplier for MBUSI, along with Tucker Jones Engineering, by two internationally renowned contractors, BL Harbart International and Gray Construction.
The project consisted of expanding the existing plant, which manufactures four Mercedes-Benz models for the North American market, to 5 million square feet. The plant includes two large body shops, a paint shop, two assembly shops and a logistics center, and each area of the expansion presented its own unique set of structural challenges.
First on that list was the scope of the requested specs for the cavernous warehouses.
“This facility is huge, and the specs they wanted were impossible to meet with traditional concrete. Traditional concrete would have cracked. So we presented our low-shrinkage concrete, Arcanum, to solve that problem,” said Bill Brasher, value added products – training and sales manager for Ready Mix USA, a CEMEX USA subsidiary based out of Birmingham, Ala. “We poured 35,600 yards of Arcanum, and there was no interim cracking anywhere within any of the slabs.”
Next challenge on the list? MBUSI’s army of car-building robots. The factory utilizes robotics to assemble the vehicles, which calls for a very strong, consistently smooth ground surface. But there were concerns that the reinforcing steel traditionally laid under concrete would interfere with the signals to the machines.
“We needed a surface that would allow the robots to operate without interference from the reinforcing steel, without sacrificing strength. Our Resilia mix, which includes steel fibers added like an aggregate, was the perfect solution,” Brasher said.
Through testing, crews determined not only that the Resilia reduced the potential for signal interference, but also that it saved time when compared to pouring concrete with traditional reinforcing steel.
For the paving portion of the project, the challenge was the timeline. CEMEX introduced a mid-range water-reducer to the paving mix, which sped up the placement of the concrete to meet the demanding production schedule.
“We were working for major international contractors, and they expected world-class, quality results,” Ready Mix USA Account Manager Alan Stinson said. “Everyone had to buy into this effort. No matter what, we always started with a safety discussion to make sure that everyone was focused not only on the job, but also on their safety and the safety of others at the site. It was a bear to put together, but in the end, everyone was pleased with what we did.”
In a single month, crews poured approximately 14,000 cubic yards of ready-mix, including nine placements of 1,000 cubic yards or more. About a month later, there were two back-to-back 1,800-yard pours.
To put that into perspective, those pours required 16 tankers of cement, six tankers of fly ash, approximately 70 loads of stone, 45 loads of sand and about 2,000 gallons of admixtures—all delivered safely and on schedule.
“We were able to supply a project of this magnitude, first and foremost, because we have good people. Everyone played a crucial role in making this project a success and providing a superior experience for our customers,” CEMEX USA Mid-South Region President Marc Tyson said. “We are proud to supply cutting-edge specialty concrete mixes that make projects like MBUSI possible.”