Paving with Recycled Materials
Recycling and other eco-friendly trends in asphalt and paving
Believe it or not, asphalt pavement is America’s most recycled material. Less than 1% of asphalt winds up in landfills. Asphalt concrete removed during road maintenance can easily be reused again in all kinds of ways, including new pavement mixtures and various engineering uses. Get more in-depth information about recycled asphalt numbers here.
But, what is the asphalt recycling process like? What other eco-friendly materials can be used in paving? What are some long-term sustainable trends in asphalt?
What are the benefits of using recycled asphalt?
You might be trying to decide whether to get new pavement, or used recycled material for your home or business. Here are a few of the benefits of using recycled materials for paving:
- Saving on construction waste. And we mean this in two ways. First, it eliminates waste that you have to spend money on removing and disposing of. Additionally, it is one less thing that has to go into a landfill.
- Conservation of natural resources. Recycling asphalt reduces oil use. Using recycled materials also reduces the need for small stones and rocks that make up the aggregate. These both reduce the demand for oil drills and strip mines.
- Construction contractors save money as well. Removing the supply chains of mining and processing means the company installing the asphalt save time and money, and those savings are passed on to their clients.
- Asphalt can be recycled many times.
- Decrease in wear and tear on asphalt. Recycled asphalt is generally stronger than new asphalt. This is because of the added mineral fillers and organic fibers used in the recycled material. Recycled asphalt is less likely to crack and develop holes.
The Asphalt Recycling Process
First, asphalt is “milled.” This means that the top layer of asphalt is removed. Once it has been milled, it goes to a plant, where it is filtered, sized, and used for making new pavement. In this way, asphalt can be used time and time again, extending its life and saving money consumers, taxpayers, while conserving environment.
Asphalt pulverization is used to recycle asphalt without moving it from its job site. The surface layer is ground up and blended with the lower layers, making a new sub base.
Pulverizing is a popular recycling method for a few reasons. It’s fast and easier than removing the asphalt and replacing it. It’s cheaper to do than milling. Finally, because it uses fewer materials, it’s more environmentally-friendly than milling as well.
Laying the recycled asphalt
- Clean the surface of any foreign debris like branches and leaves. Fill in large cracks and holes with sand, and break up large clumps of dirt. The idea is for the surface to be clean and smooth.
- Fill the area with asphalt until it is about one inch deep. Use rakes or other tools to make the area flat after laying the asphalt.
- Tamp down the surface with a tamper. This is a tool for compacting the asphalt to remove air bubbles and ensure it is properly dense.
- Steamroll the asphalt. This further compacts it and ensures it melts together as one piece.
- Seal coat the asphalt. This helps prevent future weather and water damage.
Other pavement recycling
Concrete is removed, and broken down via crushing into certain sizes. Other materials, like rebar, reinforced steel, paints, and contaminants are then removed. Once the material is purified by removing other materials, it can be reused as concrete.
This process is cheaper than getting new concrete. Disposing of heavy concrete is costly, as it costs money per-ton to take to a landfill. Of course, it is eco-friendly to recycle it as well, as it removes the need of mining more rock for concrete production.
Asphalt roof shingles are more difficult to recycle since they’re easily contaminated by outside sources and other roofing materials. Dangerous materials like asbestos are sometimes used in roofing and insulation, so someone recycling shingles has to be careful and conscientious. Other things, like waterproofing, nails, plastic, cellophane, adhesives, and paints can also contaminate the asphalt roof shingles. Asphalt shingles use a higher ration of oil to aggregate than pavement, so recycling the shingles lowers oil demand by more per ton than recycling pavement.
Other environmentally friendly trends in paving
Open concrete grids
You’ve probably seen these before. Open concrete grids are made from square shaped cinder blocks with large holes in them. They are laid out in a grid shaped pattern, and the holes are filled with soil and seeded with durable plants. In the end, they look like checkerboards, but instead of black and red squares, the squares are green, with gray, concrete lines separating them.
Benefits of open concrete grids are many. They allow drainage, as water can easily pass through. They prevent erosion, as the earth is held in place by hard concrete, and they are strong enough to handle vehicles.
In porous pavement, the aggregate is held together, but not with so much binder that it is impenetrable. The porous pavement can be permeated by water. As water can flow through it, this pavement is more sustainable because it is less likely to get cracks and damage from standing water.
These resemble closely-set stone pathways. Permeable pavers allow water to flow through joints or holes in the pavers themselves. They often look like natural stones, while being able to withstand weights similar to standard pavement. Again, these are more sustainable because by allowing water to pass through, they don’t develop cracks during the freeze-thaw cycle or other issues from standing water.
Looking for sustainable paving solutions?
Whether you are looking for asphalt paving, seal coating, recycling, or anything else about pavement, Reliable Paving has you covered. We are professional paving contractors with over 35 years of experience. Not only are we happy to help and give estimates on projects, we’re capable of large-scale paving operations for homes and businesses. Feel free to send us a message with whatever paving-related query you may have.