The Largest Football Stadium in the USA 

High strength concrete thanks to admixtures

Strength and durability were especially important for the foundation, floor, sub-structure for the spectator seating, and further supporting parts made of concrete. It was particularly important to achieve high-strength for the concrete foundations that hold the steel arches, as they curve over the stadium and hold the gigantic retractable roof.  The concrete had to reach a compressive strength of at least 55 MPa in only 28 days. For other applications, concrete with a compressive strength of 28 to 35 MPa was sufficient. A high-range water-reducing admixture was called for in order to attain the stipulated concrete strength. The choice: PS 1466, a latest generation admixture based on polycarboxlyate chemistry. The concrete plasticizer increases the concrete's compressive strength, improves the workability and allows flexible mixture proportions, which means that the concrete can also easily be poured into sloping shapes.

Waterproofing solutions

To ensure the longest service life possible for the structure, it is extremely important to prevent premature corrosion and thereby provide complete waterproofing solution of the spectator area. BASF developed a complete moisture control system for this record-breaking structure, from the joint sealants to the deck coating. This system is comprised of Sonolastic® NP 2TM, Sonolastic® Ultra, Thorocoat® 200, Sonoguard® Topcoat and Conipur® 295.

Expansion joint systems

The systems from Watson Bowman Acme do more than just ensure the necessary leeway for movement between rigid elements. They also protect the entire structure and thereby ensure its sustainability, while at the same time meeting the high aesthetic demands of the project. In the VIP boxes, Wabo®Contour and Wabo®Allure expansion joint systems ensure smooth, almost invisible transitions in the wall, ceiling and floor areas. Because architectural finishes require different colors and surfaces, these systems are the perfect fit for a variety of uses, and do not stand out visually. In heavily frequented areas, such as the spectator seating or the lounge areas of the bowl-shaped stadium interior, Watson Bowman Acme expansion joint systems provide a stable, secure, and water-tight seal of the joints between concrete elements. The package solution for the expansion joint system also included safety systems such as Wabo®FlameGuard II, which was developed to guarantee the structure’s required fire resistance, minimize the spread of fire or smoke through joints, and accommodate dynamic movement.