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Key Insights

Quick Facts

  • Name: Salesforce Tower Chicago
  • Location: Chicago, Illinois
  • Customer: Ready-mix partner in Chicago
  • Client: Salesforce
  • Size: 60 stories, 837 feet tall
Challenge: Reduce the embodied carbon of construction materials such as concrete and steel, while maintaining structural integrity for a high-rise building.
How Arcosa Helped
  • Our Solution: Arcosa provided lightweight aggregate for the structural lightweight concrete, which reduced the building’s overall weight and contributed to sustainability goals.
  • Why Lightweight Works: Lightweight concrete enabled the use of thinner slabs and fewer materials, resulting in a 19% reduction in carbon emissions, less steel usage, and improved construction logistics.

Final Results

  • 27% reduction in concrete volumes, 9% reduction in steel usage, and a 19% overall reduction in carbon emissions.

Key Quote

“Less material and a faster schedule—that’s a win-win.” – Bill Wolfe, Marketing & Technical Manager

Context:

  • Considerations: Lightweight concrete offers sustainability benefits and cost savings without sacrificing strength or durability, making it a versatile option for high-rise construction.
  • Lessons Learned: Lightweight concrete can be effectively pumped to great heights, even with site access limitations, while maintaining desired structural properties.
Explore Further

Discover more about Arcosa Lightweight Aggregates and their applications in large-scale commercial construction projects.

Salesforce Tower Chicago: Pioneering Sustainability with Structural Lightweight Concrete

Salesforce Tower Chicago, standing at an impressive 60 stories above the Chicago River, is a groundbreaking project in more ways than one. As the first building in the city to require and measure Environmental Product Declarations (EPDs) to quantify embodied carbon of construction materials, this achievement is largely attributed to the use of structural lightweight concrete.

“We worked with one of the largest ready-mix producers in Chicago, and despite site access limitations, they successfully adjusted the mix design to maintain the specified unit weight while pumping lightweight concrete to 60 stories without issue,” says Bill Wolfe, Marketing & Technical Manager for Arcosa Lightweight.

The Role of Structural Lightweight Concrete in High-Rise Construction

Structural lightweight concrete (LWC), made with expanded clay or shale (ESC) aggregate, is a tried-and-true solution for commercial building construction. It not only addresses weight and durability concerns but also provides significant cost savings. Thanks to the use of LWC, fewer construction materials were required, and the construction schedule was accelerated.

LWC allows for thinner gauge steel decking, fewer steel beams, and thinner concrete slabs, due to its superior fire resistance. If normal weight concrete (NWC) had been used instead, additional steel beams and thicker slabs would have been required to meet fire resistance standards, increasing the dead load and complicating the construction process.

In fact, using NWC would have required thicker steel decking to provide the necessary stiffness to carry the extra dead load. Extra steel beams would have been required in each of the 22 column bays across all 58 stories. The use of LWC, however, reduced the number of crane picks, streamlining the construction process.

Improved Sustainability and Reduced Emissions

At 837 feet tall, the Salesforce Tower saw significant sustainability gains through the use of LWC. The building experienced a 27% reduction in concrete volume and a 9% reduction in steel usage, which contributed to an overall 19% decrease in carbon emissions.

“Using lightweight concrete means you’re able to use thinner floor slabs, which in turn means fewer raw materials, less equipment to transport and place the concrete, and less energy consumption. It’s an exponential effect across the entire building—making it a sustainable choice all around,” explains Wolfe.

Strength, Durability, and Flexibility

Despite being lighter, the strength of structural lightweight concrete is comparable to traditional concrete, leading to reduced load-bearing requirements. This translates into cost savings in both materials and foundations. The use of ESC aggregate ensures the concrete’s durability while providing architects and engineers with more design flexibility and options for the structure.

“Less material and a faster schedule. That sounds like a win-win to me,” concludes Wolfe.

The success of Salesforce Tower Chicago highlights the value of structural lightweight concrete made with Arcosa Lightweight in modern high-rise construction. Its ability to reduce material use, speed up construction schedules, and enhance sustainability makes it the ideal choice for developers looking to build tall while minimizing their environmental footprint.