Like an artist unveiling a new creation, Tappan Zee Constructors, LLC (TZC) removed enclosing formwork to reveal the first of the New NY Bridge project’s vertical piers on Nov. 13. The column is the first of 86 piers that will stand in procession across the river to support the new bridge’s road deck.
The piers begin as cages of galvanized steel bars, called rebar, around which formwork is built. Next, semi-liquid concrete is poured into the formwork, filling the empty space around the rebar cages before it begins to cure, or harden. The coloration of the partially-cured piers will lighten and become uniform as they harden over the coming weeks.
TZC carefully monitors and maintains the temperature of the concrete as it cures to ensure its full design strength is reached. Curing is a chemical process that produces heat, which is controlled by wetting down canvas that is draped over the concrete.
“Completing the first piers is a major milestone for the project,” said Darrell Waters, TZC president. “After more than a year of foundation work, it’s gratifying for our entire team to see the bridge starting to take shape above the water.”