Rondout-West Branch Bypass Tunnel
This New York City Department of Environmental Protection (NYCDEP) project, Rondout-West Branch Bypass Tunnel, is a roughly $1 billion project that will repair leaks in the Delaware Aqueduct. Currently, site-work is being completed in Newburgh and Wappingers, where two new shafts will be built to allow for the construction of the 2.5 mile bypass tunnel. The shafts will be 900 and 700 feet deep respectively, and they will be more than 30 feet in diameter.
HVEA is responsible for concrete mix design and trial batching in our AASHTO Accredited Laboratory. During trail batching, representatives from NYCDEP, Schiavone, Parsons, and Haks Engineers witness the operations. We test fine and coarse aggregates (specific gravity, absorption, magnesium sulfate soundness, gradation, organic impurities), and we evaluate the mix design to determine quantities. Each mix consists of four water/cement trial points with varying amounts of several admixtures. Following a full array of tests, we determine the acceptable trial point and make recommendations for concrete production to the client and owner.
We mapped the heat signature of the selected mix in-situ so that the DEP could have confidence that the concrete would not develop cracks due to excess heat. We related the heat signature early compressive strength, and developed a protocol to strip forms.