Long View

Northeast Prestressed meets surge with $8 million plant investment

IMAGE

Vice President Dennis Fink oversaw upgrades to equip the Cressona, Pa., operation for Pennsylvania DOT-rooted public-private partnership activity, along with major bridge contracts in Mid-Atlantic and Northeast markets.
Yard

The new batch plant and enclosure front NPP’s girder production building. PHOTOS: Advanced Concrete Technologies
IMAGE

Ramp up of mix production capability plus girder and deck panel fabrication—all tied to the Goethals Bridge and Pennsylvania Rapid Bridge Replacement contracts— began in 2015. Advanced Concrete Technologies configured a modular MobilMat Mo4500-5-WCS batch plant for construction along the exterior of NPP’s main girder production line.
IMAGE

Now enclosed, the batch plant has a 4-yd. ACT/Wiggert HPGM 4500 planetary countercurrent pan mixer and 600 tons of heated aggregate storage. A skip hoist loads the mixer, which discharges via a chute through the wall to crane buckets waiting on the other side. A two-position shuttle cart, located just below the mixer discharge chute, can hold two crane buckets. The crane operator can place an empty bucket on the cart and immediately pick up a full bucket without wait time.
IMAGE

IMAGE

The WCS Control System also allows for unattended, automatic batching or remote control from production floor or crane call stations. It affords intuitive color-coded real-time display of critical elements of the batching process, as well as tracking of production statistics and reporting for material consumption, inventory, and maintenance scheduling.

Northeast Prestressed Products (NPP) is laser focused on delivering the highest quality precast and prestressed products for transportation infrastructure in the Northeast and Mid-Atlantic states. Coupled with investment of $8 million over the past two years in a new batch plant, steerable trailers, 70-ton gantry crane, forms for concrete deck panels and box beams, and battery molds for precast bridge abutments, NPP’s dedication is paying deep dividends.

In early 2014, the Cressona, Pa.-based producer was named one of three primary precasters to supply structural components to the $1.5 billion Goethals Bridge Replacement Project, a public-private partnership (P3) between the Port Authority of New York and New Jersey and NYNJ Link Developer LLC. NPP prepared to fabricate nearly 400 prestressed concrete bulb-T beams measuring up to 178 ft. long and 8-ft. deep, and weighing up 110 tons, along with 6,000-plus partial-depth deck panels.

Later in 2014, it was named the primary precast supplier for another P3 endeavor, the Pennsylvania Rapid Bridge Replacement Project, between the Pennsylvania Department of Transportation and Plenary Walsh Keystone Partners. The program will replace 558 aging bridges throughout the Keystone State. NPP is supplying an array of modular precast bridge components, including footers, abutments, wing walls, columns, pier caps, deck panels and parapets.

TIME TO CAPITALIZE

By 2015, NPP was producing around the clock and hired more than 60 new employees to help meet demands posed by the two huge P3 contracts. Yet, the producer needed even more capacity and more capabilities. One of the key targets for improvement was to update a 15-year-old concrete batching system, which occupied 3,000 square feet of valuable production space under the main bridge crane. The aging equipment took up to 10 minutes for each mix bucket load, and was not able to reliably produce self-consolidating concrete.

Each of the largest Goethals Bridge girders, for instance, required approximately 50 yd. of high performance concrete. The old batching system took nearly two hours to output sufficient mix for one beam. “We knew what we needed to do, but getting it done was a logistical challenge,” notes NPP Vice President Dennis Fink. “We had to find a way to locate the new batching system in its own enclosure outside the plant to free up our critical production space. We could not afford any significant interruption in production while converting to the new system.”

Adding to the challenge was the fact that NPP’s new batching system would have to be certified by all of the DOT and allied agencies the producer works with before it could go into service.

WISH LIST

In early 2015, Fink and NPP President Thomas Koons narrowed down a search for a new batching system. After considering several proposals, they chose the modular MobilMat Mo4500-5-WCS batch plant from Advanced Concrete Technologies (ACT), of Greenland, N.H. NPP’s wish list for new equipment and companion overhaul work included:

• Move the batch plant outside to free up space under the production building’s main overhead crane;

• Protect the new batch plant from the weather, including heated aggregate storage for all-season production;

• Provide significantly more aggregate, cementitious material and admixture storage capacity;

• Incorporate a high shear mixer capable of producing high performance concrete, including SCC, as well as consistent 4-yd. output, even when faced with variability in aggregate specific gravity and angularity;

• Reduce batching cycle time and provide flexibility and increased mix distribution;

• Provide a higher level of system automation; and,

• Reduce or eliminate overtime required for batch system cleanup.

ACT worked with NPP’s local contractor, Kinsley Construction Inc. of York, Pa., on the details of site preparation for the new batch plant, including an insulated enclosure to house the new batching system and aggregate storage bins. Mechanical contractor James Craft & Son Inc. of Manchester, Pa., created the aggregate storage heating system using miles of radiant heat tubing over a bed of 6-in.-square reinforcement wire mesh to provide a precast heated floor for the 600-ton aggregate system.

NPP built its new batch plant and aggregate storage system directly outside of the main production building from its old batch plant. “It was a logistics nightmare to ensure that we could still produce with the old batching system while we were building the new plant just outside,” observes Tom Koons. “We managed to get it done within a five-day window over a long weekend. Not only did we have to start up the new system while we were simultaneously removing the old batch plant, but we also had to certify the new batch plant with our DOT and P3 partners. Everything had to be verified and certified, including scales, mixer, admixtures and water metering.”

SOLID RETURNS

IMAGE

NPP’s 80,000-sq.-ft. production facility has shouldered fabrication of prestressed bulb-Ts up to 178 ft. long for the Goethals Bridge contract, along with more conventional beams for P3 projects throughout Pennsylvania. Installation of a new batch plant immediately outside the facility freed up critical production space and cut in half the time required for casting crews to receive 4-yd. mix loads. PHOTOS: Advanced Concrete Technologies
Beam2 max crop

IMAGE

Delivery of the super girders commenced in late-2015 on overnight schedules, whereby NPP could arrange escorts for local thoroughfares and along Pennsylvania and New Jersey stretches of Interstate 78. NPP beefed up its fleet with steerable trailers from Nelson Mfg., some bearing up to 32 wheels. The route from Cressona, Pa., to the Goethals Bridge site in Elizabeth, N.J., totaled 120 miles. Consistent with hauling permits, the girders were festooned with LED and conventional trailer lights. PHOTOS: Concrete Products
IMAGE

The list of benefits NPP derived from the capital investments over the past 24 months is long. When it comes to its new batch plant, highlights include:

• Reclaimed approximately 3,000 square feet of critical crane bay space, enabling the producer to cast 6,000 prestressed deck panels for the Goethals Bridge contract.

• Achieving high early strength sooner, thanks to the new batching system’s increased energy and accuracy. “Usually two to four hours sooner,” Dennis Fink observes. “We achieve from 9,500 to 13,000 psi within 24 hours in most cases. That level of early strength gives us the extra time we need for the complex set-ups and still allows us to maintain our 24-hour production cycle.”

• Greater production output. The ACT MobilMat Mo4500 batching system has cut NPP’s mix cycle time from 10 minutes to about five per batch. “What used to take us 10-12 hours, we can now do in eight,” Tom Koons affirms. “We can produce more product every day.” NPP output has increased by 10,000 additional yards of concrete per year over the past five years.

• Increased production flexibility.

• Reduced overtime. NPP’s batch plant features an automated cleanout system that reduces manual mixer cleanup and maintenance requirements. The company is saving more than $20,000 per year in labor tied to mixer cleanup.

• Improved accuracy and consistency. The new batch plant’s computer control system enables NPP to consistently produce high performance mixes, including SCC. The control system automatically measures and compensates for moisture, keeps detailed records of every batch, provides maintenance reminders, tracks inventory and automates reordering.

• Improved safety. Strict lockout systems and safety interlocks on the new batch plant greatly reduce the chance of accidents.

Another milestone is a key NPP customer’s recognition of the new batch system’s automated moisture measurement and compensation using microwave probes in the aggregate bins and mixer. “We’re offering our DOT and P3 partners a new, higher level of batching consistency and accuracy with continuous moisture monitoring and correction,” notes Fink. “With our new batching technology, you are placing your faith in science and technology rather than from a single moisture reading taken by a person from the bottom of a 120-ton aggregate bin.”

“Our firm is in great shape for the next 10-20 years,” Koons concludes. “We are state-of-art across the board at this point and capable of delivering whatever high quality products that our DOT and P3 customers demand. Our recent investments are already paying off in every way imaginable.” — Prepared by Hank Giles for Advanced Concrete Technologies