Should You Use Recycled Asphalt?
Reduce, reuse, recycle. We all know that using recycled materials is an important way to do our part for the environment.
However, when it comes to paving at your home or business, you also want the best quality money can buy. Is recycled asphalt the way to go, or will it cause problems later on?
In this guide, we’ll explore everything you need to know about asphalt so you can decide if recycled asphalt is right for you or not. Keep reading to learn what you need to make an informed decision.
What is Asphalt?
First, let’s take a closer look at what asphalt actually is, so you can understand the difference between new and used asphalt.
Asphalt on its own is black, sticky, and gooey is liquid. It’s made of petroleum, which can be found naturally, and can also be refined in a factory. Asphalt is a type of pitch. Because it’s naturally black, we get the term “pitch-black” from asphalt.
You’re probably most familiar with asphalt being used on roads and driveways. It’s been used as a paving material for a long time. Of course, straight asphalt is sticky and wet, but when mixed with grainy particles, the result is asphalt concrete.
Asphalt concrete makes great roads, although it can come with one problem: it will melt in extremely hot temperatures. That’s why every so often, there is a news story about the roads melting during extra-hot days.
You may also see asphalt on roofs, where it’s used to waterproof, protect, and seal.
The word “asphalt” is often used to talk about both natural and refined forms, but refined asphalt is what is typically used for paving and other practical applications. This refined asphalt is made using petroleum, rather than found in natural sources.
Formation of Asphalt
Naturally-occurring asphalt is essentially a fossil fuel: it’s created from the remains of long-dead organisms. It’s most tiny organisms like algae that created asphalt.
When those organisms died long ago, their bodies ended up on the bottom of lakes and oceans. Thanks to a combination of intense pressure, heat, and time, those remains were transformed into things like petroleum, which can be refined into what we know as asphalt.
History of Asphalt
Asphalt was used long before recycling was even considered as an option.
It was used to waterproof a basket as early as 5,000 BC. In the 3rd millennium BC, civilizations in the same area were using asphalt to waterproof much larger structures, such as the Great Bath.
Ancient Sumerians used natural asphalt as a cement for brick and stone buildings, and to caulk the hulls of ships, among other things. In ancient Egypt, mummies were sometimes embalmed using natural asphalt.
Access to asphalt was helpful, and some cultures even battled over access to natural asphalt pits.
Asphalt was not widely used in Europe until the end of the French revolution in 1830. Suddenly, asphalt was in high demand in France, and the people used it for roofs, pavements, and other practical applications. This rise in popularity was linked to the discovery of natural deposits that were discovered in France.
In the U.K., asphalt was mainly used for etching before it was used for building city structures. In the 19th century, knowledge about using asphalt as pavement in France was brought to the U.K.
A number of people around this time developed patents for asphalt and used it for many entrepreneurial activities, such as flooring. Many people tried to claim that their type of asphalt was superior to the rest.
In North America, indigenous people were the first to use asphalt. Natural asphalt was found to be an excellent adhesive, and it was also used to seal canoes.
In the U.S., asphalt was first used to pave roads in the 19th century.
Modern Uses for Asphalt
You may choose to pave a driveway or another area around your home or business with asphalt or recycled asphalt. However, just as throughout history, there are also many modern uses for asphalt aside from paving.
Roofing is the second-most-common use of the material. Other uses include sealing the outsides of buildings and other structures, lining pools and reservoirs, coating cables and pipes, and even making newspaper ink.
However, asphalt concrete for paving is by far the most common form of asphalt today. These concrete mixes are usually about 5 percent asphalt, mixed with 95 percent gravel, sand, or stone to create a durable material for paving.
The asphalt cement is heated to the melting point so it can be thoroughly mixed with the aggregate material.
Asphalt pavement has to be maintained. Milling, or removing part of the surface in order to smooth it out, is a common form of asphalt pavement maintenance.
After milling, the layer that was removed can be taken back to an asphalt mixing facility and recycled. Since so many roads today are paved with asphalt, it makes sense to recycle some of this material.
From airport runways to highways to homes, asphalt is all around us, and it’s often reused after removal. Is recycled asphalt the best choice for you? Let’s take a closer look.
How Often is Asphalt Recycled?
Asphalt is easy to recycle. In fact, it’s one of the most common materials for recycling in the U.S.
According to the Federal Highway Administration, as much as 81 percent of asphalt that’s removed from roads gets recycled.
Turning used asphalt into a like-new material is very simple, which is why reused asphalt is so common.
Why Use Recycled Asphalt?
What are the benefits of recycling asphalt?
In 2002, for environmental reasons, the Federal Highway Administration publicly stated that it would recycle road paving materials, including asphalt, as much as possible.
Not only was recycled asphalt better for the environment, but it even appeared to be stronger than new asphalt. This meant that roads built with used asphalt were safer and longer-lasting, giving the FHA another incentive to recycle.
Not only that, but recycling saved money when it came to building and maintaining roads. It turned out to be cheaper to recycle asphalt than to create new aggregate mixes every time.
The money saved could then be put into maintaining and building roads even more effectively, making this a win-win situation.
Recycled Asphalt and the Environment
Recycling asphalt makes a huge difference for the environment. The material can take up enormous amounts of room in a landfill, and it doesn’t biodegrade at all.
Used asphalt could be mixed with new asphalt, it was discovered, to make the virgin material stronger. This also means that less new asphalt needs to be made, which takes away some of the burdens of manufacturing.
Asphalt mining is destructive to the area in which it’s done. It also uses a lot of water, so it’s better not to use these natural resources any more than necessary.
Of course, transporting heavy materials like asphalt also uses a lot of gasoline, releasing extra pollution into the air. When asphalt can be recycled at a nearby facility, instead of mined, refined, and shipped from far away, this takes away a huge environmental toll.
Is Recycled Asphalt Expensive?
Actually, used asphalt is cheaper than new asphalt. It’s so easy to recycle that this is more cost-effective than using new asphalt.
Also, when natural petroleum prices go up, so does the cost of asphalt. Recycling results in a lower manufacturing costs. As the consumer, this is an obvious reason why you may want to use recycled asphalt.
How Recycled Asphalt is Made
Asphalt falls under the category of Construction & Demolition Waste. Other C&D Waste includes glass, wood, and concrete.
This waste, unlike normal waste from a household, can be difficult to get rid of. It usually has to be taken to a special center for disposal.
Recycled asphalt is typically crushed up, screened for impurities, and then re-processed. All of this usually happens at a facility. Alternatively, asphalt can be pulverized on-location and mixed for use there.
These in-place recycling processes may not be the most efficient, but they are fast. The recycled asphalt can be prepared for reuse without being transported at all.
Types of Recycled Asphalt
Let’s examine the different ways used asphalt can be made more closely.
1. Asphalt Cement Supplement
When recycled asphalt is used as a cement supplement, it provides an additional binder for asphalt cement. This means there is less need for new asphalt cement in either a new or recycled mix.
This supplementation can be done at a facility, or on location.
2. Hot Mix Asphalt: Facility
When recycled asphalt is made using the hot-mix method, it’s usually done at a processing facility. The facility will have crushers, screening equipment, and stacking and conveying equipment.
This allows the asphalt to be recycled and stocked for reuse. The final result can be used in hot mix asphalt paving in place of new asphalt.
3. Hot Mix Asphalt: On Location
Hot mix asphalt can also be made in place. This operation will use heating, compaction, and other processes that can be done on location to recycle used asphalt.
4. Cold Mix Asphalt: Facility
Recycling cold mix asphalt in a facility is very much the same as recycling hot mix asphalt. The main difference is that this asphalt will be used in cold mix paving instead of hot.
5. Cold Mix Asphalt: On Location
When cold mix recycled asphalt is made in place, the pavement is milled to the desired depth for resurfacing, then processed and mixed on location. The road is repaved and compacted without the asphalt ever being transported to the facility.
6. Granular Aggregate
Old asphalt can also be recycled to make new granular aggregate for asphalt mixes. In this process, the used asphalt is crushed and screened, then mixed with new or recycled aggregate material.
When the aggregate isn’t going to be bound with a new asphalt mix, it has to be combined with other materials to add strength. That’s why granular aggregate made from recycled asphalt has to be mixed with a different material before it can be used.
7. Subbase Aggregate
Used asphalt can also be crushed, screened, and made into a stabilized base aggregate material. Again, it will need to be mixed with other materials before it can be strong enough for use.
8. Fill Material
One more purpose for used asphalt is as a fill or embankment material. This is not necessarily the ideal use for used asphalt, but it happens on occasion.
When recycled asphalt is used as fill material, it’s usually because there is extra asphalt left over from other projects, and it needs to be disposed of responsibly.
Is Recycled Asphalt Right for You?
Still not sure if used asphalt is the right way to go? Let’s take a quick look at the pros and cons of using this material.
Asphalt recycling is good for the environment. If not recycled, old asphalt will stay in the landfill forever.
It’s also very durable – as much, if not more, than new asphalt.
There are some potential quality issues you can run into with used asphalt. Sometimes, the recycling process can create quality issues that turn into cracks or potholes later on.
Used asphalt also doesn’t retain its color as long as new asphalt does. Since it’s been exposed to sun, rain, and other weather already, the material is already primed for discoloration.
If you’re committed to the classic black asphalt color, the recycled material will not hold onto it for you, and you’ll want to use new asphalt instead.
Thinking About Paving with Recycled Asphalt?
Whether you go the new or recycled route, it’s important to get your paving done by a professional.
Trained experts will know how to work with both new and recycled materials. You’ll also need to get your asphalt maintained professionally. If you try to repair, seal, or otherwise fix asphalt on your own, you might end up permanently damaging it.
If the asphalt has already been used, that professional maintenance is even more important to keep it sturdy as long as possible.
Looking for help getting new or used asphalt paving done at home or work? Contact us today to learn how we can help.