STORY BY JANIE ROSMAN
Limited concrete placement continues on the bridge project since the December 16 accident involving one floating concrete batch plant that resulted in Tappan Zee Constructors, LLC (TZC) shutting down both batch plants while it continues to assess the situation.
“One of our floating concrete batch plant silos had a structural failure that caused all three silos on the batch plant to collapse,” TZC President Darrell Waters said in a statement last week. “The damage appears to be limited to the affected silos and part of the surrounding structure.”
Limited concrete placement will continue as Tappan Zee Constructors, LLC (TZC) continues to investigate what happened with one of the two floating concrete batch plants, per project officials’ December 26 press release. Activities on the Westchester and Rockland landings continue “as originally scheduled as this work has always been planned to receive the needed concrete from trucks to the site.”
Concrete for those foundations near Rockland’s South Nyack shorelines will be from local concrete suppliers via trucks. While TZC is working to get the batch plants online, it is using the Thruway southbound access ramp and will exit the trestle to the Thruway via the northbound access ramp.
“People on River Road will not notice a difference,” TZC spokeswoman Carla Julian assured. “It’s always been planned that the land work will have concrete trucks for the abutment. We redesigned the road for longer acceleration.”
Each truck holds about 10 cubic yards of cement, she said, and pours are not more than 200 cubic yard. The bridge builder is working to get the batch plants online, realizing the time restrictions regarding the cement pours. There will be two or three trucks of curing concrete the access road since trucks have to be placed before it concrete cures.
Curing is a process that protects concrete from losing moisture and within a reasonable temperature range.
Brian Manning, P.E., Executive Vice President and Chief Development Officer, Sterling Construction Company, Inc., has worked with TZC members Fluor®, Traylor Bros, Inc. and Granite™ on several occasions.
“They’re professionals and know what to do in every situation and should recover just fine,” Manning, Technical Region Director of the American Society of Civil Engineers, said.
“TZC did the right thing by shutting down the batch plants and assessing the situation for safety,” he said. “They found alternate means, which is the right thing to do, and they’re making sure it (what they’re doing) is safe.”
In a similar situation, he said, his company would do take the same action. “We would stand down, evaluate what happened, and make sure it won’t happen again.”
Tilcon New York, the New NY Bridge project’s leading supplier of stone, temporarily ceased deliveries — and removed its material-containing barges moored the site — until further word from TZC in early 2015.
As the investigation, and the project, continue, “Safety and environmental stewardship are our top priorities,” Julian and Waters said.