Residential and commercial recycling programs are available almost anywhere you are. These programs have saved millions of pounds of trash from going into landfills. They also prevent the use of resources to create new materials when recycled materials are available. But did you know that nearly one-third of all landfill in the U.S. comes from construction and demolition? If we really want to make an impact with our recycling efforts, we can’t ignore this massive source of waste. Many recycling centers accept a surprising variety of materials that wouldn’t normally go in your residential recycling bin. Construction and demolition recycling can reduce landfill and limit the use of resources for new materials manufacturing. It can also help you score points for LEED certification. Avoiding waste can even benefit your bottom line. You’ll design and build using fewer materials and send less of your materials straight into the trash.
What is Recyclable?
When we think of recycling we often think of the blue bin we send out to the curb once or twice a week. Our little residential bins accept paper, plastic, metal, and sometimes glass. If you’re willing to visit a recycling center in person, you can often recycle bulbs, batteries, and many electronics. But when it comes to construction and demolition recycling, you’d be amazed at the variety of materials many recycling centers are able to accept and reuse.
Some materials that can be recycled include:
- Rigid plastics
Humans produce more concrete annually than any other artificial material on earth. One of the main ingredients in concrete is sand, and a vast sand mining industry spans the globe with operations all over the world. Sand mining has become so intense and so profitable that many illegal sand mines have popped up. These illegal mines cause considerable environmental damage on top of the somewhat controlled damage caused by sanctioned mining operations. In developing economies, sand mining operation may also be exploitative of local populations. India, in particular, has seen a rise in criminal gang and mafia control of sand mining operations.
Concrete production is also one of the largest single contributors to CO2 emissions worldwide. When concrete goes into landfills, the resources that went into producing the concrete are completely wasted. However, when concrete is recycled, the raw materials are almost 100% recoverable. Used concrete can be crushed to into gravel or dry aggregate to make new concrete, relieving the need for new sand and gravel.
When concrete is recycled, it must first be stripped on any other trash materials. Once the concrete is clean, it is crushed, and the various-sized pieces are sorted for gravel or aggregate production. Rebar in recycled concrete is sorted out with giant magnets and sent for separate recycling.
Dirt, Rock, and Sand
At the end of each working day, the open face of a landfill must be covered over with a layer of soil referred to as ‘daily cover’. The daily cover seals off the newly deposited waste. It helps prevent vectors, such as flies and mosquitoes, from picking up diseases from the trash and spreading them to animal and human populations. It also helps prevent fires and blowing trash. Sealing off the trash also reduces animal scavenging activity.
Using fresh soil for daily cover damages precious topsoil and leads to further environmental damage around landfills. Dirt, rock, and sand recovered from constructions and demolitions waste can be used as ‘alternative daily cover’ (ADC). ADC reduces the need to disturb the land around a landfill and gives new usefulness to material that would have otherwise become landfill itself.
Cardboard, Paper, Plastic, and Metal
We think of these materials as the typical fare of home and office recycling. However, construction and demolition can also produce large amounts of cardboard, paper, plastic, and metal. Packaging alone accounts for much of the cardboard, paper, and plastic at a new construction site. During demolition, a large amount of metal may be removed that is no longer useful to the construction crew. All of these materials can be used to create new post-consumer products, just like your home recycling.
Cardboard and paper are shredded and soaked to create pulp for new paper products. Much of the packaging used today is already at least partially composed of post-consumer materials. Recycling this material sends it through a second or even third cycle of reuse. This kind of recycling dramatically reduces the need for trees and other natural materials to make paper and paper products.
Plastic is generally shredded and melted down to make new plastic products.
Metal can be smelted and used to create new metal projects. However, construction sites often have different types of metal than your typical residence. Demolition sites often have large amounts of copper wiring, sheet metal made of steel and other alloys, and plumbing made of a variety of metals. These are valuable as scrap metal and can actually turn into a source of profit for demolition crews.
In older structures, crews may uncover a significant amount of lead, such as in piping. If this lead is allowed to go into landfills, it can leach into groundwater and contaminate local water sources. Proper disposal and recycling can keep lead out of landfills and even give it new life for other applications.
‘Inert solid waste’ includes concrete, asphalt, dirt, brick and other rubble. It is one of the main ingredients in asphalt roads. Inert waste is usually used as the bottom layer of a roadbed.
Lumber and Other Wood
Wood, of course, comes from trees. While many paper products already come from post-consumer materials, lumber is almost exclusively sourced from adult trees. Reducing the amount of timber waste directly translates into reduced demand for timber.
There are two ways to reduce lumber use. The first is to minimize waste and maximize use. One way to do this is to use standard sizes when designing structures. By using standard lumber sizes in construction, the amount of cutting is reduced. This can translate into labor and time savings, and it also results in fewer wood scraps and less sawdust. In addition to reducing wood scraps, reusing wood scraps presents both financial and environmental benefits.
When wood is no longer usable for construction, it may still be valuable for recycling. Common products made from recycled lumber include mulch and biomass fuels. Some types of small wood scraps can also be used in the manufacture of engineered wood products.
Deconstruction Instead of Demolition
One way the construction industry can save more material from landfills is to shift from a demolition model to a deconstruction model. In deconstruction, workers avoid wholesale destruction of existing structures. Instead, they take apart structures with the aim of saving valuable and reusable materials. Reusable materials include reclaimed lumber, porcelain fixtures, tiles, hardware, and plumbing. Doors, windows, and appliances can also be reused. Often these larger structural elements can be sold or donated to programs that build homes for low-income or at-risk individuals.
Tracking Cost Savings
Construction and demolition recycling is a great way to benefit the environment while also saving money. To track savings as well as your other expenses you can use Needo’s construction management software. Contact us to learn more.