Story at a glance:
- The Astria Project combined a novel cement with a concrete mix design tailored for multiple structural demands.
- Together the cement and admixture system supported increased strength, placement consistency, and more.
In Tempe, Arizona, adjacent to the Arizona State University campus, the Astria Project is serving as a field demonstration of high-strength concrete performance with CalPortland’s ADVANCEMENT HPT, Type 1T ternary blended cement in a 27-story student housing structure.
Developed as a privately owned tower and placed by Suntec, the project represents one of the first western US high-rise applications of Type 1T cement in structural concrete ranging from slab-on-grade placements to high-strength vertical elements.
At the center of the project is ADVANCEMENT HPT, Type 1T ternary blended cement, produced with approximately 20% clinker replacement. The cement was selected to support the performance demands of a high-rise schedule progressing at roughly one floor per week, while also demonstrating that a lower-clinker cement can be deployed in high-strength applications without sacrificing constructability, consistency, or strength development. In the concrete, Chryso Optima 1130 (Type F) and Chryso Zyla 625 (Type A) were used to support workability, placement efficiency, and finish quality across varying structural elements.
Cement and Concrete Performance
The Astria Project combines a novel cement with a concrete mix design tailored for multiple structural demands. Concrete strength targets included 4,000 psi for slab-on-grade, 6,000 psi for decks, 10,000 psi for lower-level columns and shear walls, and 8,000 psi for upper-level vertical elements.
Natural pozzolan was already incorporated within the cement, so no additional supplementary cementitious materials were introduced in the concrete mixture, avoiding redundancy while maintaining a controlled, performance-focused design.
Innovative Cement Application
Photo courtesy of Suntec
ADVANCEMENT HPT, Type 1T ternary blended cement was evaluated in this project not as a niche sustainability trial but as a structural cementitious solution capable of meeting demanding structural performance requirements. Its use in decks, columns, and shear walls demonstrates that the system can support both elevated strength classes and the production consistency required for large-volume urban placements. Because this application is among the first of its kind in the western US, the project also provides valuable field validation for broader Type 1T adoption in high-performance concrete.
Concrete Mix Design
Within the concrete mixture Chryso Optima 1130 contributed water reduction and rheology control needed for pumpability and placement consistency, while Chryso Zyla 625 supported overall mix stability. This admixture package was particularly important for maintaining predictable field performance across repeated pours in a fast-cycle high-rise schedule, where finishing windows, set consistency, and reliable placement behavior directly affect productivity and quality.
Performance Optimization
Together the cement and admixture system supported several key outcomes during construction:
● High-Strength Capability: Concrete strengths ranged from 4,000 psi slab-on-grade placements to 10,000 psi lower-level columns and shear walls.
● Placement Consistency: Stable rheology and pumpability supported predictable placement and finishing performance.
● Schedule Support: Reliable set characteristics and strength development helped maintain a construction pace of approximately one floor per week.
● Quality Assurance: Enhanced monitoring, including sampling from every pour, provided additional confidence in performance consistency throughout construction.
Overall the Astria Project demonstrates that Type 1T ternary blended cement can perform in a demanding high-rise environment when paired with a disciplined mix design, appropriate admixture technology, and close field monitoring. The project provides an important reference point for future high-strength applications seeking both performance and reduced clinker intensity.
Carbon Dioxide Reduction Potential
With approximately 25,000 cubic yards of concrete placed on the project, ADVANCEMENT HPT, Type 1T cement provided an opportunity to reduce embodied carbon relative to a traditional Portland cement benchmark. Based on published GWP values, the cement offers approximately 18 to 19% lower embodied carbon, illustrating the role lower-clinker technologies can play in supporting both high-performance concrete applications and carbon reduction objectives.
Suntec’s Perspective
As the concrete contractor Suntec has played a key role in placing and finishing the concrete under demanding field conditions. Despite the project’s innovative material approach, the concrete has delivered the workability, consistency, and pumpability needed to keep construction moving efficiently.
“Hitting 3K at 24 hours kept us on schedule, but it was the consistency in set times that made the difference in the field,” says Austin Kirkpatrick, vice president of construction. “Our finishers knew exactly when to be on the slab every single pour, and the mix stayed workable enough to deliver the finish quality we expect on every Suntec job.”
With the concrete supporting a pace of approximately one floor per week, Suntec is now on track to complete the project roughly two weeks ahead of schedule.
Ongoing Collaboration
The Astria Project highlights the value of collaboration between Chryso and CalPortland in validating innovative cement technologies under demanding field conditions. Through admixture selection, field performance support, and close monitoring during placement, the project illustrates how coordinated mix design, admixture selection, and execution can reduce risk while validating concrete performance under demanding construction conditions.
“Astria is an important example of how advanced concrete admixture technologies can help meet the demanding performance requirements of a high-rise structure,” says Angela Slone, district manager for Chryso, emphasizing the project’s technical significance. “For Chryso this project demonstrates how the right admixture approach can support consistent placement, workability, and overall field performance in a complex structural application.”
Lauro Rivas, vice president of technical services for the materials group, underscored the project’s significance. “The concrete mixes, enhanced by Chryso’s Optima 1130, with extensive testing from our cement and concrete research labs, have exceeded the required early and ultimate strengths without impacting project schedule. The workability, pumpability and overall performance makes this project a true testament to innovation. Being part of this venture that not only challenges the norms but also sets new benchmarks in quality is incredibly gratifying.”
