Every year, Holcim U.S. Inc. ships more than 15 million tons of cement, making it one of the largest cement manufacturers in the United States. It produces and sells both ready-mix concrete and aggregates to numerous customers, including concrete product manufacturers and concrete dealers. So it seems ironic that a company which begins making cement by crushing rock would turn one of its processing plants into just that — crushed rock.

The Holcim plant in Laporte, Colo., was constructed in the 1940s. That plant continued to produce cement until recently, when a newer and more updated complex was built in the region. With the old building site lacking the new technology, including anti-pollution devices, it was abandoned.

There were several structures on the 120-acre site including a pre-heat facility, clinker storage, a raw mill, a baghouse, the machine shop, a compressor building, a cement cooler, and approximately 25 silos which were used for bulk storage. The land needed to be cleared and turned into usable property that could then be resold.

Since Holcim is environmentally conscious, most of the material in its buildings would have to be recycled. Although various contractors submitted a bid, it was Cherry Demolition which won the project, due in part to both its long-standing relationship with Holcim and its commitment to recycling.

Throughout the years, Cherry Demolition has done a lot of projects for Holcim nationwide. The Houston-based company began as a family-owned house demolition business in 1952 and has grown to include environmental and crushed concrete divisions.

Last summer, the company secured the Holcim contract and in September, sent 25 people to Colorado to begin demolition. But before the wrecking ball and excavators took over, Cherry Demolition subcontracted LVI Environmental Services Inc. and Risk Removal to dispose of the asbestos in each building.

From there, the demolition team began using six excavators, a couple of off-road trucks, a dozer, a loader, and numerous pieces of smaller equipment, including an HB 3000 hydraulic breaker from Atlas Copco. The crew first imploded all the buildings — including the pre-heat building, which was the tallest at 275 feet — and two smokestacks, leveling them to the ground. They were then able to bring the excavators in to finish breaking up what was left of the reinforced concrete in each structure.

Instead of imploding each silo, they were taken down the conventional way — with a 150-ton crane and an 8,000-pound wrecking ball. Since excavators can only reach approximately 31 feet high and the silos stood 120 feet, the wrecking ball was necessary. But once the structures were within reach of excavators, the Cherry Demolition team switched to the HB 3000 hammer to finish the job. "We changed to the hammers for the lower part of the building so we could continue with production," said Robert Cantrell, job superintendent on the Holcim project. "Once we finished using the wrecking ball on one structure, we moved to another building while the hammers finished the first facility."

Between all the buildings included in the plant and the silos, the Cherry Demolition team processed 12,500 tons of carbon steel, including 6,000 tons of steel in the pre-heat building alone. Cherry Environmental Services then recycled the materials, including the rebar, structural steel and copper. Even the equipment was taken out and resold. "The materials will become I-beam, H-beam, railroad track, or even rebar again," said Cantrell. "This helps us to reduce any waste."

The only part of the site that wasn't recycled was the reinforced concrete. "Customarily, we will recycle all of the concrete we demolish," said Rick Cherry, co-owner of Cherry Demolition. "But this time, [Holcim] had asked that we leave it there in their on-site quarry. It will then become part of the land and will be sold for future development."

Cherry Demolition broke up 83,000 cubic yards of reinforced concrete, using its Atlas Copco HB 3000 for a large majority of that work. With a service weight of 3 tons, the HB 3000 is capable of delivering an impact rate of up to 540 bpm. The HB 3000's size was ideal for the Holcim project, as it provided the right amount of pressure for breaking up the concrete. "The hammer did extremely well at the job site," said Cantrell. "We really liked the hammer's features, including AutoStop and AutoControl."

AutoStop and AutoControl are just two of the many features of Atlas Copco's Krupp percussion technology. Another feature, AutoStart, allows the operator to start hammering regardless of whether the chisel point is in contact with the material. In AutoStop mode, however, the hammer will not fire until the operator applies down pressure on the demolition tool via the carrier. AutoStop eliminates the damaging effects of blank firing. "When you're doing demolition and you break through the concrete, the AutoStop feature stops the hammer when there's no pressure applied to the tool," said Cantrell. "By stopping the hammer, the possibility of internal damage is greatly reduced, thus the life of the hammer is increased."

Cantrell also liked the AutoControl feature, which always begins in short-stroke mode for easier tool positioning. With AutoControl, the hammer senses the hardness of the material it is on and controls the hammer's stroke accordingly. This automatic adjustment system reduces excess shock on both the hammer and the carrier, and lengthens the service life on tension bolts and retainer bars. "We were able to increase efficiency with the AutoControl feature," said Cantrell. AutoControl, another exclusive feature for Atlas Copco hammers, finds the optimum ratio between the impact energy and frequency to maximize performance whatever the material.

Another characteristic of Krupp percussion technology Cantrell liked is ContiLube® II, as it helps reduce production time. ContiLube II is a continuous lubrication unit which mounts directly on the hammer box. Utilizing a compact, self-priming pump, ContiLube II eliminates the need to manually grease the hammer before each use.

"The ContiLube II feature on the HB 3000 was really helpful," said Cantrell. "It is so simple to use, too. We just screwed the cartridge onto the lubricating port, and the system pumped the grease from the cartridge into the hammer. When it got close to empty, we just changed the cartridges and continued working.

"On a normal hammer, you might stop almost every four hours to grease it and check everything," Cantrell added. "But with this hammer, it's a lot quicker. You just screw the cartridge in and you're back to work. The time it takes to get out and grease a hammer the usual way eats into your production. Over a week or two, it can really add up. With the ContiLube, there's less lost time and our production time was a lot lower."

Although Cantrell enjoyed the features of the HB 3000, this wasn't the first time he had encountered Krupp percussion technology. In the past, Cherry Demolition had used hammers marketed by Allied Construction Products, which exclusively sold Krupp tools in the United States and Canada. However, in June 2002, Atlas Copco purchased the Krupp hydraulic hammer business, thus making Krupp percussion technology standard on all Atlas Copco hydraulic breakers.

At a National Association of Demolition Contractors meeting, Cherry Demolition approached Atlas Copco representatives and discussed purchasing a new hammer. "We have used several different hammers in the past," said Cantrell. "But Atlas Copco has refined the Krupp technology to be an even better product. This is a new innovation and has been refined as much as a hammer can be. We're glad we purchased it. It made our job easier, and in the end, sped up the project."

Prior to the Colorado project, after Cherry Demolition purchased the HB 3000, Atlas Copco representatives visited the company to test their product. "We had already installed the breaker, Atlas Copco came down and did flow tests on the machine to make sure the hydraulic flow was adequate," said Cantrell. "Since then, we have purchased that breaker and plan to keep the machine and hammer together because we know everything fits well.

"Not only did they help us adjust the tool for maximum performance, they also showed us how to operate and maintain the tool," said Cantrell.