Salesforce® Tower Chicago

CHICAGO’S SALESFORCE^® TOWER SHOWCASES THE ARCHITECTURAL POTENTIAL OF AEOS^® STEEL

At the confluence of the three branches of the Chicago River, a new silhouette graces the iconic Downtown Chicago skyline.

Salesforce Tower Chicago is making its debut as the 17th tallest skyscraper in the Windy City. This emerging steel marvel will feature 1.2 million usable square feet and stand 60 stories above the peninsular 333 Wolf Point Plaza.

Also known as Wolf Point South, Salesforce Tower Chicago is the third construction project of the Wolf Point master plan. This three-phase development plan by Pelli Clarke Pelli Architects is putting the final touch on one of the only remaining riverfront plots in the Windy City—a prime location for commerce, transportation, and civic activity.

Engineered for Sustainability. Designed for the Future of Work.

From ground level to the top floor, Salesforce Tower Chicago will boast a glass-clad exterior framed by high- strength steel. The secret to this tower’s glass-plated structural soundness lies within the beautiful synergy of architecture and engineering and the most advanced high-strength steel available domestically.

In order to achieve the design of a glass facade and column-free corners, Magnusson Klemencic Associates (MKA), the Engineer-of-Record, and Walsh Construction, the General Contractor, opted for Nucor’s new Aeos^® high-strength steel.

Aeos, which stands for Agile, Optimized, Efficient, and Sustainable, is North America’s only domestically produced A913 steel. This advanced steel is not only strong enough to meet the engineering requirements for a tower of this magnitude, but flexible and structurally versatile enough to achieve the project’s innovative architectural vision.

Nucor produces Aeos from over 90 percent recycled metal, and both the material produced and the company’s waste is 100 percent recyclable as well. Plus—Nucor’s sustainability mindset also informs Aeos’ structural capabilities.

“As we looked at structural options for the Salesforce tower, it became clear that structural steel was the best solution for this particular project,” Dave Eckmann, PE, SE, Senior Principal for MKA said. “Certainly taking advantage of the high-strength steel in the project reduced the column sizes, which reduced the [size of the] enclosures, which made it more desirable to the architect and actually creates more leasable space for the developer.”

Aeos’ incredibly high strength-to-weight ratio enables greater architectural ingenuity—and greater cost- efficiency for the developer and the fabricator.

We automatically jump to grade 65 recognizing that it’s readily available and it provides a material savings to our clients—and I think all engineers should take advantage of this.

Dave Eckmann, PE, SE,
Senior Principal, MKA

Elliot Wilm, Assistant Project Manager for Walsh Construction, also lauds Aeos’ advantages in the Salesforce Tower Chicago project.

“Salesforce Tower is a concrete core with a concrete podium up to just below the street level. After that it’s structural steel from level one all the way up to the top,” Wilm said. “Using a higher strength steel allows you to keep a smaller section size, reducing its embodied carbon. Some of the columns that we’re picking down on the west side are 50-something thousand pounds. At that point, if it was made out of lesser grade steel, it probably would cause an issue with the crane and its capacity.”

Due to Salesforce Tower Chicago’s bustling location, transporting and erecting massive pieces of steel poses inevitable logistical challenges. But this high-strength alternative to traditional steel has proven surprisingly advantageous throughout the construction process.

“In the future, I do see structural steel continuing to be developed constantly with higher strength steels, smaller sections, more efficient designs,” Wilm said. “It’s definitely not going anywhere. We know that it’s got a good use in office buildings and taller floor conditions, longer span conditions. It’s been working out well so far, and it’s going to keep going.”

ROLLING WITH THE PUNCHES

Design Changes, Learning Curves, and Game Changing Benefits

As with any construction project, Salesforce Tower Chicago had a few adjustments along the way. When Cives Steel Company, the project’s fabricator, was faced with an unexpected design change, they turned to Nucor for material that would get the job done—fast.

“On the Salesforce Tower [Chicago] project, we actually had a design change after all material had already been ordered,” Brian Wessel, President and General Manager at Cives Steel Midwest said. “The owner wanted to change the height of a few floors within the building, which ultimately required reordering several column sizes, at which point we approached Nucor and were able to get into the next rollings and got the material ordered and delivered here on time without any real effects to our fabrication timeframe.”

Although the new A913 steel posed a short learning curve for the welding processes, Cives quickly realized the advantages of fabricating with grade 65 steel.

“One of the exciting things with grade 65 material is the potential for elimination of the preheat requirement that you would find with normal grade 50 material when welding,” Wessel said. “We’ve really found that benefit to occur when splicing two grade 65 members together. I will say, initially, a lot of our welders were apprehensive in not performing the preheat. However, as we’ve worked on more and more of the projects requiring grade 65 material, our welders have become more comfortable with it and are now actually eliminating the preheat on a number of splices in our shop where we’re welding grade 65 material together. So there’s a lot of possibility there for time savings in the shop, and that can translate into the field as well.”

Salesforce Tower Chicago is far from completion, but it’s already defining Chicago’s urban epicenter—and the future of steel construction.

“I feel the future of the steel industry is very bright,” Eckmann said.

With the innovations that we’ve seen over the last number of years with higher grade material, availability of material domestically, shorter lead times, there are just so many things that provide a real bright future for the steel industry.