The village closed off the Jefferson Avenue Bridge on Nov. 25 to allow for the sealing of cracks on the bridge’s wear surface, but still needs to address the bridge’s guard rails that do not meet code.
By JACKSON CHEN
It has been three months since the re-opening of the flawed Jefferson Avenue Bridge, but a preliminary report shows that numerous errors during the construction process may be to blame.
On Nov. 25, beginning at 6 a.m., the bridge was closed off so the contractor, Arben Group, could apply an epoxy sealant and binder to the numerous cracks running through the wear-surface of the bridge. The bridge was reopened the following morning and the process was completed at no cost to the village.
According to Village Manager Rich Slingerland, the wear surface is a four-inch thick layer of concrete, reinforced with steel, poured on top of the primary bridge structure. The wear surface’s purpose is to protect the bridge underneath in terms of durability.
The cracks in the wear-surface, noticed by nearby residents, began shortly after the bridge was completed in August. According to Gina von Eiff, a Jefferson Avenue resident, the cracks were continually widening as they soon spanned the entirety of the bridge.
Eric Cowley, a Harrison-based forensic and structural engineer, said “fresh concrete will always crack; it’s a matter of controlling the cracks.”
Slingerland said the cracks were originally determined superficial, but were ultimately recommended to be sealed after a report from John Deerkoski, a Warwick-based engineering consultant hired by the village for an independent review. Based on the preliminary reports obtained by the Review, there were several factors that could have contributed to the widespread cracking on the bridge’s wear surface.
According to Deerkoski’s report, there were numerous factors that could cause additional cracking on the bridge based on New York State Department of Transportation, DOT, studies. Deerkoski noted in his report that there was a low water to cement ratio that causes a higher strength in concrete. However, according to the consultant’s report, “early-strength gain can be considered a contributing factor to the observed cracking.”
During the pouring of the concrete, a low water to cement ratio was noted in one of the daily work reports prepared by WSP Group dated Aug. 24. However, the contractor continued with the pour under the guidance of the project engineers, WSP Group.
Besides the low ratio, the report also noted the premature starting of the pouring process. DOT recommends a 12-hour gap after pre-wetting, a process that hydrates the dirt below the structure and creates a more solid foundation. According to the same daily work report, the contractor pre-wet the deck just before the start of the pour at approximately 8:15 a.m.
Deerkoski also noted that the welded wire fabric, which serves as the concrete’s metal reinforcement during the pour, wasn’t properly supported and was picked up when the concrete began to cure. The removal of the welded wire fabrics “obviously disturbed the curing and the final performance of the overlay,” Deerkoski said in the report.
He added in his findings that “the pour shouldn’t have been allowed to start. The contractor should have known better. WSP who was at the site certainly should have.”
Amidst the many initial faults of the project, the village is still discussing whether to pursue litigation against the contractors, Arben, who also broke a sewer line in March of last year. After Arben’s accidental break in the sewer line, which caused three million gallons of raw sewage to leak into the Mamaroneck River, the village was left with a $17,000 fine from the New York State Department of Environmental Conservation.
The village has since remedied the cracks but the pedestrian guard rails are still below the required height as designed by WSP. The current guard rails, which are highlighted by orange netting covering it, measure around 35 inches tall, which is below the 42 inches of height required to comply with safety standards for pedestrian-use bridges according to the state transportation department.
“During the process, the drawing is created and it’s run through all kinds of people looking at it,” Cowley said of the common practices of construction. “It goes through the designer, goes through town officials who have their own consultants. A lot of people would’ve probably reviewed the design or drawings.”
When asked why the guard rails are at the incorrect height, Slingerland said the village had received a letter from the Army Corps of Engineers in 2009 advising that the protective walls alongside the bridge’s upper should be open and low as possible to not trap debris from extreme flooding conditions. However, the village manager added that even though the letter was taken into consideration, it doesn’t negate the current requirements of height for the guard rails.
According to Slingerland, the village is looking to correct the guard rails as soon as possible, but is waiting on quotes from WSP. Afterwards, the new rails would be manufactured and installed after meeting the correct codes and requirements.