A wrecking ball and dynamite can certainly raze a building. But for many contractors performing demolition work, a more precise tear down with excavator-mounted demolition attachments can be a more cost-effective and lucrative proposition.
"With a wrecking ball you end up with a mixed pile of rubble," says Jeff Malarik, Atlas Copco. "Mixed rubble needs to be taken to a landfill or separated off site. This requires hauling fees, tipping fees, etc., all of which add to the cost of the project."
Specialized excavator attachments, on the other hand, can serve as primary demolition tools to tear down structures, then operate as secondary tools to process and/or sort debris into piles that can be sold at a profit, hauled to a recycler or used on site. "The ultimate goal is to use everything on site, because you can save on the cost of transportation and labor," notes Jim Lafon, Geith. "And it's better for the environment."
Malarik sees such "selective disassembly" as an emerging trend. "It's sort of reverse construction," he states. "It's just more economical for contractors to take structures apart selectively - to put various materials in their particular place, rather than having them mixed together in a big pile, move that pile, then sort the pile. It's more economical to move any one thing once."
"To be able to process debris on the jobsite and leave most of the material behind can be a substantial advantage to the contractor," agrees Curt Helmen, Genesis. For example, a structure that's made mainly of reinforced concrete can be separated into two piles, one with concrete, the other with rebar. "The contractor saves in the cost of not having to move trucks in and out," he says. "He also ends up with rebar that can be sold as scrap steel. In this scenario, he could own the attachment several times over on the very first job."
On-site processing options
Last year's high value of scrap steel and record fuel prices created an environment ideally suited to demolition attachment use. While the recent drop in prices may change some aspects of on-site steel processing, recycling will continue to be a driver in the growing popularity of these attachments.
"I see more and more activity with tools that can process demolition debris on site so it can be recycled," says Rob Murray, LaBounty. "A lot of jobs are being bid around it because of the cost of fuel and transportation. If you can process debris on site instead of hauling it off and hauling crushed material back in, you're saving a lot of money."
There are several options to assist in this process, ranging from shears and pulverizers to multi-processors and grapples. Shears are a good choice for cutting through heavy steel or structures made with reinforced concrete, whereas pulverizers are a good choice for munching away at predominately concrete structures, including those with rebar or steel mesh. Many of the models in these categories can be used for both primary and secondary demolition.
"Before these attachments, the only other option contractors had for processing concrete was a concrete crusher," says Helmen. "This is still an option for some jobs because of the output advantage a crusher provides. But it's also a more expensive option because of the investment in the equipment and the expense of moving it in and out of the jobsite."
Size for size, shears and pulverizers are typically more powerful, but multi-processors have the advantage of greater versatility thanks to multiple jaw sets. "These units can be set up for broad or specialized applications," says Lafon. "We have a concrete jaw that does nothing but initial concrete breaking. If you want to take that same debris and reduce it to a manageable size, you can install the pulverizing jaw."