Pavements

The Definition, Uses, and Benefits of Perpetual Pavement

What is Perpetual Pavement?

Perpetual Pavement is an asphalt concrete pavement that is designed to last 50 years or longer without any repairs below the wearing course (surface level).  It typically has a multi-layered structure which resists fatigue over time. The triple-layered structure resists structural damage for as long as the top surface is maintained and replaced. While the outer surface is cared for, the rest of the pavement will not to be fully repaired or replaced for many years.

 

Resistance to Pavement Fatigue

The goal of perpetual pavement is to be a deep-strength asphalt paving that resists fatigue. It does so by reducing cracking from the bottom-up. When pavements undergo road traffic, fatigue develops from the cyclical nature and weight of the traffic. The fatigue begins as cracks at the pavement foundation. These foundational cracks then work their way up to the higher layers of pavement. As they do so, the cracks spread out and multiply. Finally, over time, the cracks show themselves on the surface of the asphalt pavement. 

Perpetual pavement is designed specifically to resist bottom-up fatigue cracking and structural rutting. These two types of damage are some of the worst that pavement can receive. It is superior to low-grade pavement that has rutting and cracking before their design-life is achieved. It is also superior to high-grade traditional pavement because it uses materials more efficiently.

 

Differences from Traditional Pavement

Empirical Pavement Design

Traditional pavement is made based on empirical designs. High-quality pavements are typically made using empirical observations. Afterwards, the pavement is designed to meet the observations made. These observations rely on the following set of factors.

1) Traffic levels.

2) An indicator of material quality,

3) Pavement material layers.

Numbers 1 and 2 interact with each other in order to predict what the appropriate levels for number 3 should be. This method is called empirical pavement design. 

Essentially, it works like a math formula. For a given material design (number 2) and traffic levels (1), the pavement material layers (3) should increase or decrease.

The flaw in empirical pavement design is that eventually the pavement thickness is more than enough for the load of traffic. Pavement will be thicker and thicker, but at no real benefit. What this means to builders is that costs will go up but not affect quality. Pavements over-designed by adding 1.5-4.5 inches of thickness added 600-1,800 tons of material per mile of single-lane road. All of this extra weight was beyond necessary levels for the function and lifespan of the road.

 

Mechanistic-Empirical Method (M-E Pavement Design)

Perpetual pavements use a different method of design than traditional pavements. This method uses more factors to create a model. The model is then used with testing and more experimentation to figure out allowable loads and damage. Once the damage level is acceptable, it is ready to go to the final design stages. 

Step 1

There are 3 inputs.

1) Materials.

2) Traffic.

3) Pavement layer thickness.

These three inputs are combined into an analytical model, which gets pavement values. The pavement values determine the allowable load (according to the model)

Step 2

Actual loads are compared to allowable loads on the model to compute damage.

Step 3

If the computed damage level is not too high, the pavement can go into the final design.

Optional Step 4

If the computed damage level is too high, the pavement layer thickness is increased, and then steps 1-3 are repeated. 

 

This methodology was originally used to test metal fatigue.

For a detailed, long-form article about perpetual pavement, as well as good flow charts showing the design process, look at this article from the Asphalt Pavement Alliance. 

 

Pavement Design Life

Regardless of the method of pavement design, a pavement’s life is based on several other factors. In general, for any type of asphalt, the design life can be seen as a function of several factors.

1) Design requirements (method used for design, M-E, or empirical pavement design).

2) Material characteristics (quality of construction materials).

3) Construction practices (quality of build/structure).

4) Layer thickness.

5) Maintenance Activities.

6) Failure Criteria (how failure is defined according to the designer).

 

Design Philosophy

  • Perpetual pavements must have enough structural integrity and thickness to stop cracking, fatigue, rutting, and deforming.
  • Perpetual pavements must be durable to resist damage from traffic and the environment.

 

Physical Design

Layer 1

1.5 To 3 inches of HMA (hot mix asphalt) or OGFC (open grade friction course). HMA is flexible and deflects, or flexes, under loading. The load is dispersed throughout the pavement so each sub layer carries less weight. OGFC is a porous asphalt allowing water to drain through it. It also reduces wet weather crashes.

Layer 2

There are 4 to 7 inches of rut resistant material in layer 2. This is high-strength material that is flexible enough to expand and contract and resist cracking.

Layer 3

Layer 3 is composed of 3 to 4 inches of durable material that resists fatigue. This is the part of the pavement that will receive the most tensile strain (horizontal push/pull). Layer 3 must be resistant to fatigue cracks over time.

Layer 4

The final layer of pavement is the foundation.  This can be compacted subgrade, stabilized subgrade, stabilized aggregate, or unstabilized aggregate like gravel.

 

Why are Perpetual Pavements Beneficial?

  •  Cyclical costs are reduced on the pavement. As long-term damage is avoided, yearly or multi-yearly-accrued damage doesn’t need to be repaired.
  • More efficient design.  They eliminate overly-thick sections of asphalt.
  • Reconstruction costs are eliminated.
  • Delays due to maintenance are fewer and less costly.
  • They reduce use of non renewable asphalts and aggregates.

 

Considering Perpetual Pavement?

If you are thinking about getting your next paving job done, and perpetual pavement seems right for you, let us know. Reliable Paving is a paving contractor with over 35 years of experience across the South and Southwest. We are happy to assist you with any questions you may have about pavement, long life pavement, and pavement maintenance.

Excavators in Paving Projects

Paving projects come in all shapes and sizes. Small jobs, like driveways, probably don’t need any kind of heavy equipment except for rolling the pavement flat after it’s laid. Larger jobs will often need heavy equipment. This is where excavators and backhoes come in.

Why does laying asphalt paving need this kind of heavy machinery? There are two main reasons. The first is when the foundation for the pavement needs to be dug deep. An excavator gets the job done more efficiently than a large team of manual diggers. The other reason is for doing repairs and maintenance on concrete. An excavator can break through damaged  asphalt concrete layers in order to get at the lower layers below. This lets pavers pour a new, flat layer of asphalt where the damaged asphalt was before.

 

What is an Excavator?

An excavator, commonly known as an earth mover, is a large, heavy vehicle with a boom, stick and bucket attached to the front end of the machine. The boom and stick make up a mechanical arm that can be used to manipulate the bucket (or claw). Usually the excavator moves by double treads along the bottom, like a tank.

There are several variations of excavators, each with a  specific function. A wheeled excavator exchanges treads for a set of wheels, making it ideal for moving around construction sites. Wheeled excavators are great for moving on terrain that is already paved. Other various kinds of excavators include suction excavators, which use high water pressure to blast materials loose. Another is the long-armed excavator, which can reach high-up and difficult spots. Check out this in-depth article about different excavator types.

An excavator is one of the largest pieces of heavy equipment available, weighing up to 200,000 pounds.                                                                                                                     

 

Alternatives to Excavators

Manual Digging

Paving contractors can use jackhammers, drills, and other single-person pieces of machinery to dig. These devices have the benefit of being light, easy to transport, and less costly on fuel. However, for large projects, numerous pieces of equipment are needed. Often, one excavator can do the work of a whole team. 

 

Backhoe

The backhoe is the workhorse of a lot of paving operations. This machine is a tractor with a mounted 2-part arm attached to a bucket. It is similar to an excavator, but smaller, and with less power. The main difference between the two is size. An excavator is simply larger and more powerful, and thus suited to bigger tasks. 

The backhoe’s use lies in its versatility. Both machines offer a wide selection of attachments, but the backhoe has more. Additionally, the range of the arm of each device is different. The excavator has a full 360 degree rotation. A backhoe only has about 200 degrees of rotation.

Over all, a backhoe is more suited to medium-sized workplaces with a wide variety of jobs. An excavator is best suited to larges scale construction projects where its size and power shine. Backhoes weigh about 20,000  pounds or less.

 

How to Choose What is Best for Your Project

The best way to choose between which piece of heavy machinery best suits you is to learn about them. Knowing more about backhoes and excavators means you can most easily make the right choice for your project.

 

Size of the Project

As mentioned before, massive projects need massive machinery, so an excavator would be ideal. This is especially true of paving projects as an excavator can break through the damaged layers of asphalt or concrete with its bucket. A backhoe will require special attachments, called hoe rams (think big hammers) for this. Get an excavator to a large project, and it can accomplish a lot, quickly and efficiently. The longer arm of the excavator also helps it move things larger distances over less time.                                                                                          

Other uses for excavators include demolition, landscaping, mining, digging holes, and moving big objects.

For small scale projects, like driveways and small parking lots it may be best to dig without heavy equipment. A team of skilled workers with drills and jackhammers could make shorter, more precise work of a smaller construction site.

 

Project Locations

If a project has multiple work locations, then a backhoe might be best. A long stretch of highway for example, might have stretches where no work is required. For this type of work, a piece of machinery that can more easily move from point-to-point is best. A backhoe can move much faster, about 25 miles per hour on pavement.                                                                            

So, if your project has disparate locations requiring frequent travel, a backhoe is probably more suitable. However, when it comes to certain tasks, like pavement and repairs, a backhoe requires a larger team than an excavator.

 

Deadlines

Despite the difficulty and cost of getting a massive excavator to a site, it’s often worth it. Repairing a frequently-used stretch of road is more important to do quickly than cheaply. Also, working in high-value locations like airports, it’s important to get work done so traffic can resume. When time is of the essence, nothing beats an excavator.                                          

 

What’s the Verdict?

Use an excavator when:

  • The project is massive
  • Deep digging is essential
  • The timeline is short
  • There are fewer people available to work

Use a backhoe when:

  • The project is small or moderately-sized
  • A wider variety of heavy tools are needed
  • There are numerous locations that must be traveled to

Use neither when:

  • The project is small                                                              
  • It is impossible to get heavy machinery to the work location

 

What Does Your Paving Project Need

Do you have a paving project? Whether your project is large, tiny, or in-between, our team of over 200 at Reliable Paving can get the job done. With 35 years of experience, we are experts in asphalt-pavement. We can install new paving, perform maintenance, and consult to help with projects as well. If you have a project, leave it to the experts. Contact us today for a quote.

Asphalt Sealcoating machine

The Right and Wrong Ways to Repave Your Parking Lot

Keeping the parking lot of your business in good working order will save money, improve business, and prevent costly rebuilding in the long run. Maintaining the parking lot correctly will help prevent deeper damage, so that deeper, more costly repairs aren’t necessary. For many visitors, the parking lot is the first experience had with a commercial space. A dilapidated, cracked lot can damage the customer’s car, and sets a bad tone for doing business. Finally, a lot that is taken care of well will be less likely to need a total reconstruction in the future. 

We’ve got some guidelines for making sure your repairs/repaving are done the right way.

Quality VS Speed

The Wrong Way: Speed Over Quality

Although it’s important to get your parking lot paved quickly when there is damage, quality comes first. You’ve probably seen asphalt haphazardly poured into a crack in a road or lot before. The asphalt bulges above the crack, it is loose almost immediately, and it is a great place to damage tires. 

The repair may have been fast, but it won’t last, and will just lead to bigger repairs and higher costs later on.

The Right Way: A Balance of Quality and Speed

Fixing your asphalt lot is important to do quickly for several reasons:

  1. Small problems can get worse. A small crack can easily get water inside. When that water expands and contracts with heat and cold, the crack can spread. The sooner you fix the problem the better.
  2. But make sure your repairs are done with quality in mind. The holes and cracks need to be filled properly. This means they need to be level with the rest of the pavement so as not to damage vehicles. It also means that they need to be properly filled, possibly with support bars inside, or with some excavation of the surrounding pavement to get a better pour.

Fixing your problems quickly and effectively is key. That way you avoid the higher costs of major repairs.

Materials

The Wrong Way: All New Materials

Believe it or not, it’s pretty much never necessary to use new asphalt. The reasons for it are twofold: 

1). It’s not environmentally friendly. New asphalt has to be made from strip-mined rock to get the aggregate material. The second ingredient is refined oil, which makes up the binder that glues the aggregate together. This binder must be pumped and go through the whole oil refining supply chain.

2). It’s more expensive. New asphalt materials cost more. Besides the supply chain mentioned above, they also have to be transported to the construction site.

The Right Way: Recycled Asphalt

Asphalt is the most recycled material in the United States. Not only can recycled asphalt be easily acquired, you may even be able to supply your own. If your blacktop is damaged and in need of repairs, as paving contractor can excavate it, pulverize it, and then lay it again to repave your lot. 

Besides being cheaper because it skips the processing steps that new asphalt goes through, recycling asphalt requires less fossil fuels and produces less pollution.

There’s no reason not to use at least a mix of new and recycled asphalt.

Maintenance

The Wrong Way: Once Yearly or Strictly Scheduled Maintenance

Regular maintenance is key to your lot being healthy. The catch basins and manholes have to be clean and free of obstructions. Obstructed canals won’t drain properly. Sitting water slowly gets absorbed into the pavement, where it damages it, causing cracks and eventually larger holes. Maintenance once or twice a year is not usually enough to clear catch basin obstructions and ensure proper water drainage.

The Right Way: Frequent Maintenance, as Well as Inspection and Maintenance After Various Events

Regular maintenance works when it is performed frequently. Depending on the weather in your location, you want the catch basins checked out at once a month or even more. That way, they can be cleared regularly and your lot will have good drainage. 

Also, be sure to inspect and maintain the lot after events like storms, floods, and earthquakes. Severe weather can damage the lot itself as well as blow branches and other debris into catch basins. If you live in a geologically unstable area, with earthquakes, tremors, and or sinkholes, regular checking can ensure your basins are clear, and that there isn’t foundational damage. 

Refreshing your lines and paint goes a long way. Fresh, bright paint on a lot gives the impression of professionalism for the business. It also makes the lot safer to drive on. Remember that the parking lot is the first part of your business that the client sees, so you want them to be safe and have a good impression.

Know When a Deeper Fix is Necessary

The Wrong Way: Resurfacing Forever

In order to cut costs, a lot of companies will simply resurface their lots until they are beyond repair. Resurfacing makes them look nicer, and is certainly cheaper than a repave, but they are rarely a long term solution for serious damage. Small cracks and holes can be fixed by resurfacing.

The Right Way: Resurface Small Faults, Repave Severe Degradation

When your lot has massive holes, deep cracks, and potholes that can damage a car, it’s probably time to repave. A well-paved lot lasts about 20 years with maintenance every 3-5 years. If it’s been over 20 years, your parking lot is without a doubt ready to be repaved.

Looking to Get Your Parking Lot Worked On?

If you think your business’s parking lot needs resurfacing or repaving, let us know. Reliable Paving has been in the business for over 35 years. We are a professional, organized, and experienced company that can do large-scale projects within strict time limits. Reliable is happy to help with your asphalt paving questions and needs. Most importantly, when you need someone to repave or maintain your parking lot, choose a contractor that’s reliable.

red volkswagen beetle parked at road side near pedestrian

Pavement and Vehicle Noise

Choosing the right pavement can help reduce noise from vehicles.

Noise can be defined as an undesired on unpleasant sound. Nobody likes a lot of noise, especially if that noise is the constant hum and roar of vehicles moving. Noise from vehicles comes from three main sources:

  1. Air passing over and around the vehicle.
  2. The engine, drive system, and exhaust of the vehicle.
  3. The tire-pavement noise. 

If you wish to have less sound around your house or place of commerce, it’s good to try to focus on number three: the tire-pavement noise.

Why is it good to reduce noise?

There are plentiful reasons to want to have less noise in your life. They range from mild inconveniences to genuine health risks. Another term for unwanted sound is noise pollution.

Noise builds stress

Having a constant background noise, especially if loud or discordant, creates stress. Do you ever wonder why it can be so hard to sleep on airplanes? The noise of the moving engine builds up internal stress in a person, especially when that person can’t move away from the noise.

The same happens to people at home or in offices when they are buffeted by the constant noise from a nearby road or highway.

Noise can cause hearing loss

This is a genuine health threat from constant noise. Thanks to our industrialized society, loud noises are a fact of life. Construction work is a major offender, as well as loud music, passing planes, and of course, vehicles. 

People who have been exposed to sustained heavy noise over a long period often develop hearing loss. The small hairs in the ear that vibrate to stimulate the eardrum can eventually break, the result is often tinnitus (ringing in the ears), and loss of hearing. 

Noise pollution is a threat to both people and wildlife. Read more about the detriments posed by noise pollution here.

How pavement can reduce noise

Changing the texture of the pavement is what primarily reduces the noise. The less friction involved, the more silently a vehicle travels. When there is less friction, there are less scraping, and humming noises coming from the contact of the vehicle’s tires with the asphalt.

Choosing the right pavement for noise reduction

Picking a pavement that reduces noise can have benefits and drawbacks. Make sure to carefully choose how you want your asphalt to be, and consider the other factors as well when making your choice.

Reducing noise on new asphalt pavement

How to

Use durable, open graded, rubberized asphalt. Open graded asphalt has purposefully designed voids within to allow water drainage. Rubberized asphalt is made from recycled materials (often old tires) blended with asphalt to produce a binder. The binder is then mixed with conventional aggregates.

Economics

Rubberized and open graded asphalt often has a shorter life than other forms of asphalt. This means repairs and replacement will be necessary more often, which can incur higher costs. 

However, the use of more recycled materials in the asphalt also provides a benefit. Landfills need less space for tires. As the asphalt is repaired and renovated, more “garbage” is used in the recycling process, lowering overall waste.

Impact

The lower sounds reduce stress in people and wildlife. The livability of neighborhoods with this type of pavement often improves.

Reducing noise on old asphalt pavement

How to
Perform repairs and coat with sealant. Repairing cracks make the pavement more uniform, as openings like potholes are a significant and disrupting source of noise pollution. Pavement preservation also reduces the formation of new fault lines, cracks, and holes in the pavement. A great way to preserve existing pavement is to seal coat it. Seal coating also has various other benefits for pavement.

Economics

Seal coating and preserving pavement is always a smart economic move. The pavement will last longer, be more durable, and require less emergency care. Seal coating is one of the main ways to reduce future pavement preservation expenses.

Impact

Because the noise is dependent on the pavement, it depends more on vehicle use. Needless to say, the smoother the pavement is, the quieter vehicles will be as they travel over it. The noise reduction improves living standards in surrounding neighborhoods and puts less stress on wildlife.

Other things to keep in mind

Friction

Keeping pavement smooth and friction-low are the two main ways of decreasing vehicle noise in a high-traffic area. However, without friction, cars won’t be able to drive at all. Friction is what gives the tires grip on the ground. 

If you are planning on installing low-friction, low-noise pavement, be absolutely sure that it provides enough friction for safe driving.

Noise pollution is nothing new, and it’s here to stay

From the advent of conversation noise pollution has been a thing. Whether it’s from unwanted music, traffic, or heavy machinery, noise pollution isn’t going away any time soon. 

Make sure that the area where you are installing the pavement will actually make a difference when it comes to noise reduction. It’s possible that a parking lot is too far away from a business to affect what’s happening inside the building. People usually drive slowly on parking lots, so a low-noise paving solution might not even be noticeable, depending on the pavement you are using. 

You can read about various countries’ studies on noise-reducing pavement and the effects in this report.

What pavement is right for you?

If you are looking to have some asphalt paving done in and around Texas, we’re the team for you. We offer paving solutions of all kinds, backed up by over 35 years of experience. Our team of over 200 can get massive jobs done in a timely and cost-effective manner. Our offerings include asphalt paving and repair, concrete repair, seal coating, parking lot striping, and assurance of ADA compliance. Reliable Paving are the asphalt paving contractors who can get the job done. If you have questions about noise-reducing paving, or anything else paving-related, get in touch with us today.

 

paving

Asphalt and Paving in Summer 2020

Predictions and analysis of the demand for paving work that will be done during the summer of 2020

COVID-19 Has Changed Almost Everything

It’s safe to say that COVID-19, the novel coronavirus that originated in Wuhan, China in late 2019, has changed the world. Almost every facet of life is now different. Masks are required in public, and in many other enclosed spaces (as well as private businesses). Large-group get-togethers like concerts won’t be happening any time soon. Almost every aspect of life has changed, and most of it for the worse.

Additionally, business is down in general. Restaurants and entertainment venues are operating at half-capacity if they’re open at all. Many businesses have closed, and won’t ever reopen. 

But what does that mean for paving works this summer? Roads are still being traversed, and parking lots still need to be safe for vehicles and pedestrians alike.

You’ve come to the right place to get that exact question answered.

 

Asphalt and Paving Works in Mid-2020

So, what about construction, and specifically paving? Riding in hot from a strong market in 2019, the asphalt and paving industry look to be in for a great 2020. 

But what about the market downturn? How has that changed the outlook for paving projects?

Fortunately, asphalt and paving seem to have weathered the storm. As we move into the middle of the year and safety measures are solidly in place against the virus, this corner of the world can move on with just a few key safety measures in place. 

 

Early 2020

With “shovel ready” projects booked from 2019, plus some hefty government funding, 2020 looked to be a boon year for the paving industry. Federal highway funding increased by $6 Billion in 2017, from $46 Billion.

Despite cautioning that business might take a serious downturn in March, however, it seems most projects have been going on as planned. Paving, particularly as infrastructure, is essential for any community, and so the paving workers were considered essential.

Here are some of more reasons why the paving industry can plan full steam ahead this year:

  • Incomplete projects from last year. Federal funding for 2019 wasn’t released until February 2019, so many 2019 projects are still incomplete and need to be finished this year instead.
  • 2020 Funding was allocated in December 2019. This means that 2020 projects could be backed-up by two years’-worth of funding.
  • FAA Airport Improvement Program (AIP). This 2020 and 2019 program provides grants to public (and sometimes private) organizations. The grants are designed to aid the planning and development of public-use airports. 
  • America’s Transportation and Infrastructure Act of 2019. This bill does quite a lot to keep the paving industry moving:
  • It increases funding for tribal and federal lands transportation programs.
  • The bill “requires the Department of Transportation to encourage each state to develop a voluntary plan that provides for the immediate and long-term personnel and workforce needs of the state to deliver transportation and public infrastructure projects.”
  • And so much more—read the bill for yourself here.

 

Summer 2020

As midyear approaches, it seems that paving and asphalt projects are still going strong. However, it also makes sense to have some cautious optimism. Here are some other factors to consider.

Funding Sources

Roughly 65% of paving and asphalt project funding comes from the federal, state, and local government. The other 35% comes from private markets, both commercial and residential. Government money is fairly reliable, since once a bill becomes law, the funding appears. The private market, however, is much more volatile. 

In the case of a disastrous second-wave of COVID-19 cases throughout the U.S., it’s possible that the private market could take a swift downturn. Additionally, as states open up and numbers of infections start to climb again, there could be another devastating market downturn. Businesses that aren’t open, schools that aren’t running, and government buildings that are shut down won’t need paving services.

 

Demand Changes

It’s difficult to predict how demand will change exactly for construction services like asphalt paving. There are several reasons, among them:

  • Much of paving needs to be done during low-business times. If a business is shut down, and has the liquid cash needed to get by until it reopens, it could go through with a paving project it had planned anyway. The project needs to be done—and with no clients, the construction can be done more easily and far faster.
  • If businesses don’t survive however because of virus levels spiking and causing closures, then demand will correspondingly decrease.
  • The stay-at-home-effect. In the case that lock-downs are again used, with only essential workers going about their business, it would be a perfect time to get city, highway, and other public works paving projects complete. The fewer people on the roads, the more efficiently workers can do their jobs.
  • Demand from government sources seems to be steady in the storm. An internet search for “paving projects summer 2020” reveals many cities and states going about their asphalt paving projects undeterred. As of late March (after lock downs and social distancing measures began in many states), asphalt and paving projects in almost all states were nonetheless ongoing.

 

We’re Still Here for You

If you need a paving project done in, you’ve come to the right place. Reliable Paving is a professional, high-quality, and extremely experienced paving contractor. With over 35 years of experience, we have the know-how and expertise to solve your paving needs. 

Come to us for asphalt paving, concrete repair, seal coating, and parking lot striping. We ensure success and guarantee satisfaction. Is your project a big one? With 19 crews and over 200 employees, we can handle large-scale projects skillfully and deftly. Contact us today to see why we are the local leader among paving companies in Arlington, Texas.

workers laying asphalt

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

Milling

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.

Pulverization

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

  1. 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.
  2. 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. 
  3. 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.
  4. Steamroll the asphalt. This further compacts it and ensures it melts together as one piece. 
  5. Seal coat the asphalt. This helps prevent future weather and water damage.

 

Other pavement recycling

Concrete

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 shingles

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.

Porous pavement

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.

Permeable pavers

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.

Noise and Road Pavement Types

Traffic noise is an environmental issue and is even called “pollution,” and for good reason. It might not belch soot into the air or contaminate water sources, but in urban areas it’s critical to take it into account so people can live comfortably (without suffocating in the thunderous noise coming in from roads outside).

The combination tire speed and pavement type is what determines traffic noise. Tire-pavement noise is made worse with rolling, slipping, or dragging tires against pavement, especially when vehicles are moving at a higher speed. Other factors that affect tire-pavement noise including the type of vehicle, temperature, weather, the age of the pavement surface, and the surface type itself.

While most of these factors can’t be controlled, the one factor you have control over is the pavement surface type. You’re able (and empowered) to strategically choose a surface to reduce noise. Using traffic noise on a typical highway as our baseline (which ranges from 55 to 80 decibels of volume), we analyzed the different types of pavement and their noise levels to help you choose the best pavement for your project.

 

Open Graded Friction Course

Open-graded friction course (OGFC) is the quietest pavement surface, producing even less noise than conventional HMA and PCC surfaces. Its noise production is estimated to 69-77 dB(A).

OGFC uses small holes (or “air voids”) in the pavement to provide a sound-absorbing negative texture. OGFC can be made with conventional liquid asphalt or with polymer-modified asphalt, including rubberized asphalt. Rubberized OGFC typically uses finely- ground rubber that’s been recycled from tires in order to change the asphalt binder in the mixture.

Because they have air voids, these OGFC varieties differ from a more conventional, densely-graded hot mix asphalt (HMA) in several key ways. For one, OGFC air voids start from 10 to 22% and usually see a little decrease over pavement life. And because of those air voids, the surface is also referred to as “porous asphalt.” These air voids absorb a large amount of noise generated by the friction of the tires and the surface itself.

 

Hot Mix Asphalt

Hot mix asphalt (HMA) can generate a noise production equivalent to 72-79.5 dB(A). HMA is made by heating aggregates to decrease the viscosity of the binding agents and make the whole mix more fluid. Then, it’s dried to remove any moisture.

HMA air void structure generally ranges from 6 to 7%. Anything above 10% gives the asphalt a shorter life. On the other hand, even if hot mix asphalt isn’t the quietest, it is considered as the most durable type of pavement—which is why it’s generally used for highways and high roads. Asphalt is weather resistant and can efficiently stand up to wind, heat, freezes, and floods. Its heat absorption, in fact, has the capacity to melt snow and ice faster than any other type of paving material.

 

Stone Matrix Asphalt

Stone matrix asphalt (SMA) is popular because of its durability and resistance. It’s considered to be a great option for high-traffic areas, including highways and interstates, as well as busy intersections. This pavement type is a gap-graded HMA originally developed in Europe.

Since this material allows less elasticity but greater resistance, it’s noisier than the two mentioned above. However, used in the right situations, it’s more cost-effective and has greater resistance over the years. Even the quietest pavement type will get noisy when it gets filled with cracks and potholes.

 

Portland Cement Concrete

Portland cement concrete (PCC) is, once again, a degree less “quiet” than the pavement types above since it generates approximately 76-85 dB(A) in traffic noise. It’s commonly made from materials like limestone, shells, and chalk or marl combined with shale, clay, slate, blast furnace slag, silica sand, or iron ore.

The difference in noise levels between HMA and PCC surfaces is a little more dramatic when PCC is grooved or tined, too (which is commonly done to improve skid resistance). However, if the surface is diamond ground, it becomes equal to HMA as far as noise reduction.

Additionally, Portland cement concrete is more economical than other pavement materials.

 

Composite

Composite is not usually used to pave roads on its own. It’s actually a mix of asphalt and concrete and it is used as a repair material for pavement maintenance. It’s often seen as an asphalt overlay for damaged areas, such as to fill cracks and potholes.

 

Depending on the location of your project, always take the road noise into consideration when choosing your pavement type. Other priorities like resistance, durability, elasticity, and aesthetic will help you make your final decision.

Though traffic noise is produced by many different factors, the pavement type has a big impact on the end noise perceived by those who live or work in the zone. Without a doubt, OGFC is the best option for areas where traffic noise reduction is of the utmost importance. However, its longevity is less than other paving options, usually needing to be repaired or repaved every 9-10 years.

Hot mix asphalt is another popular go-to since it still helps reduce traffic noise and usually lasts 12-15 years before requiring repair.

Which pavement type makes sense for your roads or parking lot? Get a free quote from Reliable Paving today.