Each month PCI Mid-Atlantic celebrates a member of our precast community. These companies collectively educate stakeholders and specifiers to advance the precast/prestressed concrete industry. Associate suppliers and fabricator companies collaborate to produce and build thousands of precast buildings annually.
This month we celebrate Splice Sleeve North America. Established in 1977, Splice Sleeve North America is a pioneer in grout-filled rebar couplers. The NMB Splice Sleeve® is a proven method for connecting reinforcing bars in concrete structures. Once connected, it performs as one continuous bar, supporting the Precast and Cast-in-Place construction industry with high efficiency.
Splice Sleeve North America’s invention, NMB Splice Sleeve®, is ideal for the precast construction industry with excellent seismic resistance and fatigue performance that doesn’t require any personnel with special certifications to make the connection.
The NMB Splice Sleeve® is a mechanical grouted coupler for splicing reinforcing bars. It uses a cylindrically shaped sleeve filled with a non-metallic, cementitious-based, non-shrink, high early-strength grout. Reinforcing bars to be spliced are inserted into the sleeve to meet approximately at the center. The interior of the sleeve is then filled with SS Mortar (Splice Sleeve grout).
The NMB Splice Sleeve® is a proven method for connecting precast reinforced concrete structural members. The sleeves are embedded on one end of the precast element at the precast plant. The primary reinforcing bars are then inserted halfway into the sleeves, with the bars protruding from the other end of the precast element. At the building site, the precast members are joined by inserting the protruding bars from the end of one precast member into the sleeves of the adjacent member. The sleeves are then grouted, making the reinforcing bars continuous through the connection. This process is called “Emulation,” and the NMB is categorized as an emulative connection for precast systems.
The NMB Splice Sleeve is designed for precast concrete instant connection, which embeds itself in the precast concrete member so that no pocket is required. The system leaves a small patchwork for inlet/outlet ports on the concrete surface for Post-Grout Systems, or even no ports are required for Pre-Grout Systems.
This system has significantly contributed to the speed of precast concrete construction without skilled workers. The first NMB project, a 38-story Ala Moana Hotel, cut eight months off the project schedule thanks to NMB Splice Sleeves. Generally, clients report 20%-time savings if using precast concrete versus cast-in-place.
Splice Sleeves exhibit high performance when used for columns, beams, walls, shear walls, foundations, slabs, architectural panels, and many more applications.
The Tower of Voices National Memorial in Stoystown, Pa., is as much a musical instrument as a monument. The 93-foot-tall precast concrete tower houses 40 custom-made aluminum wind chimes. Each chime was cast to produce a distinct musical note so that together they create a set of 40 “voices” to memorialize the 40 passengers and crew who lost their lives when United Airlines Flight 93 was hijacked by terrorists on September 11, 2001.
Precast concrete was selected for the tower frame because of the precision required to accommodate each component’s complex and unusual shapes and the strength needed to support the tall, slender frame. Paul Murdoch of Paul Murdoch Architects says, “The customizable nature of precast concrete allowed for a unique design, featuring faceted columns and diagonal, curved beams.”
Project Details:
“The elegant design is a beautiful memorial to the people aboard Flight 93; however, it created some construction challenges. The structure lacked a clean geometric starting point due to its curves, making form building and checking the pieces challenging,” says Greg Gorman, Senior Vice President and Chief Operating Officer for PennStress.
The design also required an extremely high degree of accuracy. “The use of Building Information Modeling (BIM) software was imperative to ensuring that the detailed geometry of the pieces was exact and that no interferences for the reinforcing steel, splice sleeves, lifters, electrical conduit, or various other internal components could occur,” Gorman says.
Using precast concrete also provided speed and performance benefits, says Russell Dickson, Vice President of Engineering for PennStress. “It allowed for a much higher level of accuracy due to using custom-fabricated steel forms, and easier access for checking to ensure the highest standards were maintained.” Also, because the production facility was enclosed, the team was able to produce the pieces during the winter months to maximize the construction schedule.
To read the full project profile, click here for more photos and details!
Learn more about Splice Sleeve North America’s rebar splicing solutions by watching their video or contacting them for more information.