Recycling In Place

Jan. 1, 2006

On-site crushing and screening for pavement reclamation is a major part of many road and bridge reconstruction projects. Mike Iapaluccio, project manager for J. Iapaluccio Inc., said there are very good reasons why his company practices on-site construction materials recycling. First and foremost is, he said, that one must follow the money trail. “It all comes down to the economic advantages in recycling at the construction site as opposed to hauling it away to another location.”

On-site crushing and screening for pavement reclamation is a major part of many road and bridge reconstruction projects. Mike Iapaluccio, project manager for J. Iapaluccio Inc., said there are very good reasons why his company practices on-site construction materials recycling. First and foremost is, he said, that one must follow the money trail. “It all comes down to the economic advantages in recycling at the construction site as opposed to hauling it away to another location.”

Here is how recycling fits into Iapaluccio’s operation. The company was launched into the highway and heavy construction business in 1976. Prior to that, it operated since the early 1950s as a septic-tank installation and home driveway construction firm. Mike represents the third generation of this family-owned company. He is currently following his father’s (Michael, president) company leadership. Today, the company has its corporate headquarters in Brookfield, Conn., where it employs 140 people.

The company specializes in highway, road and municipal street new construction, reconstruction and repaving. It also is active in underground utilities installations and major site-work projects.

An example of a highway construction project involving recycling that J. Iapaluccio Inc. is currently undertaking is a section of State Rte. 7. The project started in 2002 and is projected to be completed this coming November. J. Iapaluccio Inc.’s winning bid plus added change orders will total near $14 million. The contract is for Phase I. There also is a Phase II under way by another contractor for $19.8 million.

Phase I is a 3-mile-long road section that passes through the town of New Milford where the existing roadway is two lanes of two-way traffic. On either side of the road there are both residences and commercial buildings.

Breaking it down

To bring Rte. 7’s existing two-lane roadway up to ConnDOT’s current standards, J. Iapaluccio Inc. is completely removing it, including the sub-base. Under a separate contract that is jointly funded by the federal, state and local governments, J. Iapaluccio Inc. is installing a sewer line down the middle of the new highway’s alignment.

The existing Rte. 7 roadway consists of the original 10-in.-thick steel-reinforced concrete pavement that was subsequently multilayered with asphalt paving totaling 6 in. thick. J. Iapaluccio Inc. has already removed the roadway and has processed it through a portable crushing system for recycling the materials.

Here is how the removal and crushing of the pavement were accomplished. First, the in-situ concrete and asphalt pavement was cut by a saw into 10-ft by 12-ft slabs. In turn, a Volvo hydraulic excavator fitted with a hammer was used to break up the pavement slabs into 2-ft minus chunks. This chunk gradation (2-ft minus) made it suitable for efficiently feeding the portable jaw crusher.

Two different portable plant crushers were selected for the project, and both are Terex Pegson models. One is a Premiertrak 26 x 44 jaw crusher that has an input opening size of 22 in. by 44 in. The other is a Trakpactor 428 impactor. This impactor’s capacity is sized 28 in. by 42 in. Both units are mounted on track frames each featuring dual tracks for self propelling the plants. The operator who feeds the materials to the jaw crusher using a hydraulic excavator also remotely controls both crushers from the excavator cab.

The Premiertrak single-toggle jaw crusher is designed for carrying out a fast and efficient setup for making it either crushing-ready or transport-ready. It features a magnetic separator, which is a must when crushing steel-reinforced concrete pavement, and a dirt conveyor for stacking the dirt that can be present with the construction materials being fed to the crusher. Typically, dirt is present from being inadvertently mixed in with the demolished materials as they are excavated from the ground surface with a front-end loader or hydraulic excavator. The main conveyor is fully skirted and hydraulically lifted and is used for stacking or transferring the crushed materials for further processing.

Standard to this crusher is a dust suppression water spray system, because many of the crushing sites are in close proximity to either residences or commercial areas. This water spray system controls fugitive dust that is caused by the crushing and conveying of the materials.

The jaw crusher was the primary crusher in the crushing chain at the Rte. 7 project site. It handled the chunks of pavement with ease and processed it into 3-in. minus before transferring it directly to the Trakpactor impactor, which was the secondary crusher. Taking the 3-in. minus materials, the impactor reduced it to 11?4-in. minus, the wanted finished size.

There are two main reasons why the impactor was involved in the Rte. 7 project. One is that the jaw crusher cannot crush the rock down to the wanted 11?4-in. size and reach the acceptable gradation set forth in the ConnDOT specifications. Secondly, by processing the materials through a series of crushers, the throughput production rate is much more efficient.

Just enough room

The entire Rte. 7 pavement removed was crushed to use as the road’s sub-base. The crushed materials’ gradation results were within the ConnDOT gradation standards. Of significance is that no screening of the crushed materials was needed to reach the gradation specifications. Ninety-nine percent of the RMG Material (ConnDOT designation for the recycled materials) was 11?4-in. minus.

“We are very strict on our gradation specifications for sub-base,” said ConnDOT’s Dan P. Foley, P.E., District 4 engineer. “We periodically take samples from the contractor’s crushed materials stack to verify it meets gradation and that there is no more than 15% bitumen by weight included in the final road-base blend. I look at it this way, we [ConnDOT] are buying the materials from the contractor who puts it down for the sub-base, so we are going to make sure we are getting what we are specifying and paying for.”

Foley said ConnDOT has no problem with contractors using recycled materials. In fact he said the agency advocates recycling as long as the material meets the specifications. Using recycled materials usually means the contractor can reduce costs compared to using virgin materials such as quarry-crushed rock.

Iapaluccio said the use of the portable crushing equipment on the Rte. 7 project was very cost effective compared to hauling the pavement away (sometimes there is a tipping fee) and importing purchased stone from a quarry.

At this project, the two crushing plants were set up in an abandoned car wash where space was at a premium. Fortunately, the plants’ modest footprints enabled them to be set up. There was just enough room to stack the incoming broken-up asphalt and concrete where the materials-feeding excavator was set atop and just enough room for a front-end loader to load the crushed materials onto delivery dump trucks. The trucks had to be let into the loading area one at a time because there was no room to spare.

Buy and borrow

The company owns the Premiertrak jaw crusher used on the Rte. 7 project but rented the Trakpactor from the local Terex Pegson distributor, Powerscreen Connecticut Inc. The company both buys and rents portable crushing equipment. The issue of economics comes into play when deciding what is better. For example, the jaw crusher is owned because its cost of ownership is more cost effective for J. Iapaluccio Inc. than renting it.

“It all depends on how much use we have for a portable crusher. There is a crossover when the total rental costs become greater than the ownership costs, and that is when we will convert a rental agreement into a purchase agreement. Most equipment suppliers will credit a major portion of the rental fees, if not all of them, towards the purchase price,” he said.

Terex Pegson offers three types of crushers on tracks that are typically used on road pavement recycling projects. They are the jaw, the impactor and the cone crushers. Generally, if two or more crushers are set up in a series, the jaw crusher is the primary. An impactor crusher acts as the secondary if materials to be crushed are asphalt paving, concrete, concrete block or brick. If a hard, abrasive rock is to be crushed, a cone better serves the secondary spot because blow bars are fast wearing and expensive to constantly replace.

With the Rte. 7 recycling activities completed, the Trakpactor plant has been returned to the distributor; for J. Iapaluccio Inc.’s next major recycling project will require renting a cone crusher to use as the secondary. The cone is in and the impactor is out. The choice of secondary rental crushers is much to the liking of Iapaluccio. He can match the better-type crusher to the application, making the crushing more cost effective.

With many screening or crushing-screening projects in recent years for J. Iapaluccio Inc., the company owns two portable plants, including a Terex Powerscreen model Chieftain 1200 mounted on tracks.

Crushing coop

Despite using big-capacity portable crushing-screening equipment, J. Iapaluccio Inc. gets some recycling projects that are so big and with critical time constraints that an outside crushing-screening contractor is hired.

“Our portable crushing-screening systems involve one or more plants that are good for mid-size production,” he said. “For example, on the Rte. 7 site, 2-ft minus asphalt-concrete chunks were reduced to 11?4-in. minus at a rate of 1,500 tons per eight-hour day. However, there are some really big crushing projects where we must crush at a rate of 750 tons per hour to ensure this process does not slow down the construction project. We find it necessary to contract a third party who has a bigger production-capacity portable plant.”

There is a downside to using large plants. One is that their large footprint necessitates a large area to operate them and the cost associated with their mobilization. Iapaluccio said that mobilizing a large-capacity production portable plant system is very time consuming and costly, so the crushing activities must extend to at least five months to make it cost effective. Road recycling projects requiring one to four months of crushing are better carried out with the plant sizes used by the company. Iapaluccio said they usually can move their jaw crusher from one project to another in less than a day, including the setup time. He said the bigger, more elaborate portable plants used on the bigger projects take three to five days to move and set up.

About The Author: Garrett is a freelance writer in Bernville, Pa.

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