40% slag mix featured in concrete for new construction at Times Square

Given the project’s prominent location in Times Square, designers were challenged to build a new 46-story mixed use building that incorporated an early-twentieth-century, landmark-designated theatre interior while providing a contemporary space for entertainment, retail and hotel accommodation.

During a late-1980s renovation of the site, the Palace Theatre was left in place when a hotel was built above it. The 1980s hotel was constructed on an eight-story podium with super-columns at the theatre’s four corners to transfer loads from the tower. Alterations to these complex site conditions, which were required to build TSX Broadway, involved state-of-the-art demolition and construction techniques, and relied heavily on the material properties provided by concrete, such as its strength and stiffness.

The design and construction team extended the 1980s-era super columns upward and partially demolished the existing hotel tower. Three post-tensioned concrete girders were constructed between the 12th and 16th stories and tied together with concrete slabs, which allowed existing support trusses to be removed. Below-grade, caissons were drilled and concrete ring beams were installed at the perimeter of the theatre. Lifting posts and jacks situated beneath the ring beams were used to lift the theatre 31 ft above street level, and a 32-story concrete flat plate hotel tower was then constructed on top of the transfer system. As a final touch, the building’s podium was wrapped in multiple LED screens, creating a classic Times Square look.

"The use of slag cement was beneficial in multiple ways. Not only does slag cement optimise concrete’s strength, but it reduced the environmental impact of this high-profile venue by lowering the percentage of ordinary Portland cement in the mix”, said Stan Trella, Sales Manager Metro New York/Long Island, Heidelberg Materials North America.

Read the article online at: https://www.worldcement.com/the-americas/29022024/40-slag-mix-featured-in-concrete-for-new-construction-at-times-square/