Collaborating to Pioneer Low-Carbon Concrete Data Center Solutions in Arizona 

Arizona – 2022

CalPortland’s Data Center Project was a key Arizona project starting in 2022 that was slated to construct a 2.5 million square foot data center in the Greater Phoenix Metro Valley, in pursuit of LEED Gold Certification. From the ready-mix producer’s perspective, the primary challenge was to reduce the CO2 impact of the concrete used in the project. 

 

The Solution

To address the project challenge, CalPortland collaborated with concrete admixture partner Chryso. Chryso played a key role in supporting CalPortland’s development of concrete Environmental Product Declarations (EPDs) for the project and assisted with sustainability education for the team. Chryso installed a new admix tank farm to support the onsite concrete batch plant and ensured the significant quantities of admixtures, including high-range water reducers and specialty products for clay mitigation, were provided in a timely manner. Chryso Technical Sales Reps and CalPortland Plant Managers worked closely to analyze daily usage to ensure the fast-paced job needs were in-sync with admixture delivery.  

Supported by admixtures that mitigated high clay content in the aggregates, the CalPortland QC team developed a low-carbon concrete mix design incorporating 15% fly ash and 10% natural pozzolan, achieving a roughly 25% replacement of cement. To accurately quantify the CO2 impact for the concrete the project utilized EPDs to meet low-carbon concrete specifications. 

Results & Key Highlights

  • Innovative Concrete Mix Design: The collaboration led to a concrete mix design that reduced cement usage by 24%, incorporating 15% fly ash and 10% natural pozzolan. 
  • Use of Environmental Product Declarations (EPDs): This project marked one of the first uses of EPDs in Arizona to meet low-carbon concrete specifications, demonstrating leadership in sustainable construction practices. 
  • Onsite Concrete Batch Plant: The construction of an onsite concrete batch plant minimized transportation impacts and further reduced the project’s carbon footprint. 
  • Leadership in Sustainability: The CalPortland/Chryso partnership driving critical sustainability knowledge ahead of the project was instrumental in not only surpassing industry benchmarks for low-carbon concrete but in setting the table for future projects.  
  • CO2 Savings: The project achieved an overall 24% reduction in CO2 emissions against NRMCA benchmarks, equivalent to 11,262 metric tons. 
  • LEED Gold Certification: The project achieved LEED Gold certification, underscoring its commitment to sustainable construction practices. 

Concrete Volume and Mix Information

Strength  Volume  CP GWP kg CO2/ yd3  GWP NRMCA EPD*  Delta
2000  23,516  186.48  196.51  ↓10.03 
4000  58,519  235.34  247.32  ↓11.98 
4500  151,834  221.72  288.90  ↓67.18 

*NRMCA LCA Report

This significant achievement underscores the project’s success in pushing the boundaries of sustainable construction and setting a precedent for future developments. 

Lisa Barnard, LEED AP, WELL AP
Sustainability Program Manager, Chryso North America

Project Participants

Project: Arizona Data Center
Sustainability Consultant: Chryso
Ready-Mix Producer: CalPortland
Concrete Mix and Specifications:
EPDs required and a reduction from NRMCA Pacific SW industry wide benchmark (reduction percentage not specified, owner simply wanted effort made to reduce embodied carbon of the concrete)
SCM: 15% Fly Ash and 10% Natural Pozzolan
Volume: Approximately 234,000 yd3