A helpful tip: temporary roads near landfill tipping areas provide a concrete recycling application.

An interesting application where recyclers of demolition materials and landfill operators can work hand-in-hand is when concrete is recycled at a landfill and the product is used on site.

In particular, crushed aggregate material can find a home on landfill properties in a useful application that can prevent landfill operators from paying to haul virgin aggregate to their properties.

This works for a lot of reasons, but the most important one is economic--it saves money.

SAFETY FIRST

Landfills have an obligation to their customers and to the permitting entities that watch over them to maintain safe and operational facilities. One aspect of that is the creation of temporary roads to the tipping area and other parts of the landfill.

The tipping area moves constantly, and paving road surfaces that will be temporary is often not economically feasible. Yet under wet and muddy conditions, it can be difficult or even unsafe for trucks to get to the top of the cell. Additionally, mud can be tracked out of the facility and onto the street, a practice that is resented by neighbors of the landfill.

What we do is work with stone landfills to have them set aside space on site to store concrete brought in from demolition sites. Then, we bring our portable recycling crushers to the location, set them up and process the concrete into usable products, including a great product that is utilized for temporary roads at the landfill.

THE SET UP

Here's how it works. In the demolition industry, when at the demolition job site, the old adage is, "If it is in the truck, it is out of here." We don't usually have time at the site to worry about the niceties of sizing concrete to make it ideal infeed for crushers. Thus, if it fits in the bed of the truck, it is going to the disposal site.

But we have worked with landfills that give us a 200-feet by 200-feet area at their facilities. In that relatively small space, we store the incoming demolition concrete and have room to bring it down to a size that can fit into a crusher. At a time that works for our company and the landfill operator, we can set up a crushing system and still have room left over for finished product stockpiles.

The magnets on the crushers remove metals such as rebar. We call make a regular, unscreened 5-inch minus product that has Gabion stone mixed with fines and can be used for temporary roads of all kinds--at construction and demolition sites as well at landfills. Or we can screen the material and have a 3-inch by 5-inch stone for temporary roads and a 2-inch minus traditionally used as a roadbase.

Either way the landfill is saving money. The main reason is the reduced trucking costs. Currently many landfill facilities have to pay for some kind of similar material to be trucked in from either a quarry or another recycling facility.

But by having the regular demolition customers bring ill their clean concrete, the landfill is getting free raw material to make its temporary roads out of without having to pay someone to truck it over.

There is, of course, a cost to process the concrete, bur there is little cost for the landfill personnel to load material from the finished stockpiles as needed. And the crushers will not be there year-round incurring charges--just when the stockpiles grow too large.

A WIN-WIN

The response we have seen from this process has been overwhelmingly positive on the part of the people responsible for the bottom lines at their landfills.

Using the recycled concrete processed on site costs about half that of using outside stone. In addition, it can reduce truck flow slightly, and the landfill can boast that it has a new recycling operation, always good for its public relations benefits.

For the landfill operating personnel, change can be difficult at first. They have the added responsibilities of making sure the material gets stockpiled correctly, and they have to make sure their co-workers don't use too much of the material and cause sudden shortages.

The way to set up these kinds of arrangements is to have long-term agreements based on a price per ton processed. That allows the contractor to come in and crush on an as-needed basis. And it is a basis that allows a landfill to save money on a needed commodity.

GETTING THEIR FILL

While landfills can provide competition for recyclers of many C&D materials, including mixed C&D recyclers, they can also act as a consuming end market.

In addition to the temporary roads described to by Leonard Cherry, some landfill locations also accept the fines portion of material stemming from C&D recycling operations to use as alternative daily cover (ADC).

Scrap metal recyclers have also tapped into the ADC market, as operators of automobile shredding machines have been selling the non-metallic portion of their shredded stream (known as auto shredder residue, or ASR) as a type of ADC product.

The authors is president of Cherry Demolition and Cherry Crushed Concrete, Houston, and an officer with the National Association of Demolition Contractors.