Page 34 - CCD Magazine-Spring 2019

Erection of this hybrid core begins with pre-fabricated panels consisting of two structural steel plates held
in place with cross-connecting tie rods. After erection, these panels
are filled with concrete, creating a unique sandwich-style structure that provides strength and stability along with the benefits of rapid erection.
The panels in this non-proprietary system comprise two 1⁄2-in.-thick steel face plates separated by 1-in.- diameter cross-connecting tie rods; the internal space is ultimately filled with a self-consolidating concrete mix to create the final core wall assembly section. The tie rods are critical, serving to support the wall panel before concrete is poured during erection and providing confined pressure to the concrete for superior seismic performance once the erection is complete.
Traditional concrete core construction requires a complex
process of setting formwork, installing reinforcing steel, placing embedded plates, installing sleeves and block-outs, and placing and curing concrete for each level of the core. Erection times can vary, depending on core geometry, reinforcing steel congestion, and the skill level of the contractors involved, but it’s not uncommon for erection of a typical tower to take three to five days per floor.
SpeedCore erection can take place roughly twice as fast as traditional concrete core construction. In many markets, it’s possible to build two tiers (four floors) per week using SpeedCore, without waiting for concrete to cure. The steel panels
in SpeedCore construction can support up to four floors of steel floor and metal decking even before they are filled with concrete.
CF-CPSW also eliminates construction tolerance issues
involved in merging concrete construction and steel construction because steel connection plates can be welded directly to the wall panel. This avoids the dimensional conflicts that can occur with embedded steel plates in concrete. SpeedCore construction also facilitates adaptive re-use projects because the system is predictable and has no hidden reinforcing bars.
The concept of CF-CPSW isn’t new. In fact, this system has been used extensively for nuclear power facilities worldwide due to its impact- and blast-resistant qualities. Visit AISC.org/speedcore to learn more about how SpeedCore can help save time and money on your next project. Our Steel Solutions Center is always available to provide technical assistance and innovative solutions to make structural steel design even easier. Connect with the Steel Solutions Center at: AISC.org/askaisc.
Photo courtesy of AISC
34 | Colorado Construction & Design