Overlays can restore the proper transverse profile slope and improve longitudinal profile smoothness. However, the pavement must be in suitable condition. If the base is weak, you may have to remove the old and add virgin or recycled base materials in its place before you start the final overlay.
For agency jobs, Kramer said, the contractor is paving based on the bid specs. According to Mark Bolick, general manager of product support at LeeBoy, overlays are a suitable solution when:. A conventional overlay is at least 1. According to Kramer, the three most important things a contractor can do to ensure the best overlay results are to use proper planning, communication and an experienced crew.
Proper planning starts with determining the cause of the distress to figure out if an overlay will solve the problem. For example, overlays can only solve surface cracking. When it comes to performing overlays on pavement that includes rutting, Humphrey said the rutting must not be too deep. Instead, the screed will drag aggregates and the surface of the mat will be open. Moisture will penetrate in these areas and a pothole will soon develop. This will help prevent dragging aggregates under the screed and will improve the likelihood of achieving acceptable density.
To maximize the quality of your overlay, severe rutting—and any severe issues, for that matter—should be addressed prior to the installation of the overlay, Bolick said. For example, in the case of severe rutting, Humphrey recommends removing a portion of the rutted surface to a depth twice that of the rut using a cold planer.
Then, you can start planning to perform your overlay, starting with cleaning all areas that need to be resurfaced and applying a tack coat—the best practices of which have been covered in previous articles from AsphaltPro. Kramer suggests shorter hauls from the plant and making sure your haul trucks have tarps and insulated beds. That flaw will be a failure in the future. The third key is running with an experienced crew. It might not matter for thick lifts, but thin lifts? You also have to be sure to apply the right amount of tack.
Once the crew starts paving, one of the easiest mistakes to make on thin lifts is paving too fast, Humphrey said. To prevent this, he recommends choosing your speed based on the type of mix being laid and the effect of high speed paving on the grade control system.
He also suggests selecting a speed that consumes the mix in an efficient manner and planning the compaction process to match the paving speed. Another mistake he sees is selecting a mix with the incorrect aggregate size. When it comes to mix selection, Humphrey said a mix with a modified binder, such as polymer or latex, will be stickier and stiffer, and might tear under the screed at high paving speeds. Overall, he believes mix designs without modified binders are easier to apply as thin lifts.
You also need to consider the effect of high paving speed on the grade control system. At speeds greater than 60 feet per minute, Humphrey said tow point movement can become erratic. To remedy this, he recommends limit paving speeds to 60 feet per minute or less, or pave manually to ensure smoothness.
For example, he said, to lay down tons per hour at 1. However, if the thickness in this scenario was changed to 1 inch, the speed could increase to 52 feet per minute and 64 feet per minute, respectively, to maintain the TPH production rate. We have to achieve adequate density but we are limited as to the amount of force we can apply to a thin mat and we are limited in the time available.
It can also help determine the plant output temperature that will aid the compaction process. If vibratory compaction is possible, Humphrey recommends a breakdown roller with high frequency more than vpm and low amplitude drum movement between 0.
To illustrate this point, imagine a breakdown roller with inch drums and a frequency of vpm performing a seven-pass pattern.But have you ever wondered about the asphalt manufacturing process?
Oil wells supply petroleum to oil refineries, where it is separated into various factions, one of which — from the heaviest part of petroleum— is asphalt. Asphalt for paving goes through a mixing process in either a drum mix plant, which is a large-output and continuously operating facility, or a batch plant, which is a smaller-output plant that mixes in batches.
There are a few different ways to mix asphalt, the most popular of which are hot and cold. It is mixed hot at degrees Fahrenheit. It is called hot-mix because not only because it is mixed hot, it must also remain hot for the paving and compaction for repair or installation. Completed asphalt is evaluated for its quality in terms of consistency or viscosity, and purity. These are important for the asphalt to be properly controlled, transported and used in paving projects.
This specific make-up keeps the asphalt soft and helps it repel water. As its name suggests, cold-mix asphalt does not need to be warm to be used in asphalt repair. Emissions from oil refinery plants and asphalt manufacturers are rigorously controlled using equipment that re-collects the dust and particulates and re-uses them in the heating process.
This saves them from being emitted into the environment and also increases the efficiency of the heating process. Contact Wolf Paving to learn more about asphalt paving or to have your parking lot, road or driveway paved. With 75 years of asphalt paving experiencefrom highways to driveways, we are your local source for all of your asphalt paving needs.
Wolf Paving offers professional paving services from Milwaukee to Madison, and everywhere in between, including all areas around: Sun Prairie, Oconomowoc and Waukesha. Call Wolf Paving today. For the Milwaukee area, call us at For the Madison area, call us at Milwaukee: Careers Resources Blog Contact Us.
Asphalt Paving Blog. Subscribe to the Wolf Paving Blog. Mrugacz on Feb 24, The subject of this term project was an asphalt paving process utilizing a paving machine and 20 tons capacity tri-axle trucks. The location of the process was at the corner of Main and Madison in Greenwood South of Indianapolis. The project is being run by the Reith-Riley Construction Company.
The overall process involved : Hot-mix batch plant cycle Tri-axle truck cycle Roller cycle Spreader cycle Crew cycle Because of the complexity of the overall construction process, we chose to observe, report on, analyze and model the paving process on the base layer of the 15' lane road. At that time, the other lane of the road was not paved yet. The road has slightly increasing grade and curve along the process. The preliminary process of gathering the data used in this project, the efficiency of the operation, a model and MicroCYCLONE simulation of the process, and illustrations will be discussed and presented.
Asphalt has been used by man for its adhesive and waterproofing properties. Asphalt was used in B. The Sumerians used asphalt in B. Today, asphalt is applied to roofing, sealants, caulking, brake linings, paints, enamels, and most widely used in the paving industry Asphalt - Science and Technology, Process Description. First, aggregate travels through the cold feed bins, where initial proportioning of the aggregate takes place. The quantity of material leaving each bin is regulated by the size of the gate opening, or the speed of a belt, or a combination of the two.
The aggregate is sent to a drier. Here the moisture is removed and is heated to provide the proper mixing temperature in the pugmill. The aggregate continues to the hot elevator by screens to the hot bins. The screens provide the final separation of the aggregate. The different sizes of aggregate are released into the weight hopper one bin at a time.
The aggregate is dropped into the pugmill for mixing with the asphalt. The mixture is then dropped into a waiting truck or moved to a storage silo. Samples are taken from each hot bin for testing. A sieve analysis is conducted as well as gradation test.It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used. The Pitch Lake is the largest natural deposit of asphalt in the world, estimated to contain 10 million tons.
Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs. In material sciences and engineering, the terms "asphalt" and "bitumen" are often used interchangeably to mean both natural and manufactured forms of the substance, although there is regional variation as to which term is most common. Worldwide, geologists tend to favor the term "bitumen" for the naturally occurring material. For the manufactured material, which is a refined residue from the distillation process of selected crude oils, "bitumen" is the prevalent term in much of the world; however, in American English"asphalt" is more commonly used.
To help avoid confusion, the phrase "liquid asphalt", "asphalt binder", or "asphalt cement" is used in the U. Colloquially, various forms of asphalt are sometimes referred to as "tar", as in the name of the La Brea Tar Pitsalthough tar is a different material. Naturally occurring asphalt is sometimes specified by the term "crude bitumen". Asphalt properties change with temperature, which means that there is a specific range where viscosity permits adequate compaction by providing lubrication between particles during the compaction process.
Low temperature prevents aggregate particles from moving, and the required density is not possible to achieve. Specifically, Herodotus mentioned that bitumen was brought to Babylon to build its gigantic fortification wall. In French, the term asphalte is used for naturally occurring asphalt-soaked limestone deposits, and for specialised manufactured products with fewer voids or greater bitumen content than the "asphaltic concrete" used to pave roads.
The expression "bitumen" originated in the Sanskrit words jatumeaning "pitch", and jatu-kritmeaning "pitch creating" or "pitch producing" referring to coniferous or resinous trees. From the same root is derived the Anglo-Saxon word cwidu mastixthe German word Kitt cement or mastic and the old Norse word kvada. In British English"bitumen" is used instead of "asphalt". The word "asphalt" is instead used to refer to asphalt concretea mixture of construction aggregate and asphalt itself also called "tarmac" in common parlance.
Bitumen mixed with clay was usually called "asphaltum", but the term is less commonly used today. In Australian Englishthe word "asphalt" is used to describe a mix of construction aggregate.
In American English"asphalt" is equivalent to the British "bitumen". However, "asphalt" is also commonly used as a shortened form of " asphalt concrete " therefore equivalent to the British "asphalt" or "tarmac". In Canadian Englishthe word "bitumen" is used to refer to the vast Canadian deposits of extremely heavy crude oil while "asphalt" is used for the oil refinery product.
Diluted bitumen diluted with naphtha to make it flow in pipelines is known as " dilbit " in the Canadian petroleum industry, while bitumen " upgraded " to synthetic crude oil is known as "syncrude", and syncrude blended with bitumen is called "synbit".
The oil sands of Alberta, Canada are a similar material. Neither of the terms "asphalt" or "bitumen" should be confused with tar or coal tars. Tar is the thick liquid product of the dry distillation and pyrolysis of organic hydrocarbons primarily sourced from vegetation masses, whether fossilized as with coal, or freshly harvested.
The majority of bitumen, on the other hand, was formed naturally when vast quantities of organic animal materials were deposited by water and buried hundreds of metres deep at the diagenetic point, where the disorganized fatty hydrocarbon molecules joined together in long chains in the absence of oxygen. Bitumen occurs as a solid or highly viscous liquid. It may even be mixed in with coal deposits. Bitumen, and coal using the Bergius processcan be refined into petrols such as gasoline, and bitumen may be distilled into tar, not the other way around.But, when you stop and think about it — with a truly unbiased opinion — the sight of a road construction crew rolling out a brand-new batch of asphalt or concrete patching products should be a cause for celebration, wonder and awe, not frustration, annoyance and anger.
An asphalt paving project is a highly sophisticated process, requiring careful planning and the systematic juggling of any number of steps.
Shop Paving Supplies. And so, in a salute to what is probably one of the most underappreciated industries in our nation, we thought we would offer a brief look at how to repair asphalt roads. Below are just a few of the items that must be considered before beginning road maintenance:. The area on which the road will be laid must first be cleared of all vegetation, trees, shrubs and bushes.
After this process is completed, the next steps involve shaping, mounting and grading the surface:. During this final phase, the asphalt is poured and laid. Take note: Depending on the estimated traffic volumes and regional climate conditions, the asphalt paving job can require up to four different layers of asphalt:.
These are just a few of the steps involved in paving a road. In reality, the entire asphalt paving process can take years to complete. And while knowing how a road is paved may not help you reach your destination any faster, we hope it gives you something to think about the next time those orange barrels slow you down.
At Unique, we strive to provide top-quality asphalt repair and concrete patching products for your business or municipality. Explore all of our patching and pavement preservation products today. Unique Paving Materials Blog. How a Road is Paved Posted on: July 28th, by uniquepaving. Have you ever stopped to think about the different steps needed for safe road maintenance? Shop Paving Supplies And so, in a salute to what is probably one of the most underappreciated industries in our nation, we thought we would offer a brief look at how to repair asphalt roads.
After this process is completed, the next steps involve shaping, mounting and grading the surface: Mounting : Mounting gives the road its shape. During this stage, a combination of excavation machinery and bulldozers are used to move and mount dirt and soil across the road. Grading: After the road has been mounted it then needs to be graded.
Using a combination of manual labor and planning machinery, called graders, the surface layer is smoothed and leveled.So please, take a look at this step-by-step overview of what an asphalt pavement installation requires — from demolition all the way to a smooth, new surface.
The first step in the asphalt installation process is to remove the existing surface, whether it is asphalt, concrete or pavers. With a clean slate, technology helps Wolf Paving asphalt professionals prepare the surface for appropriate water drainage.
Once the sub base is fully graded and compacted, Wolf Paving completes an extra step, called a proof roll, to ensure the underlying surface is strong and ready to support new asphalt. If the proof roll finds soft areas in the sub base, Wolf Paving makes the necessary repairs in compromised areas to ensure the entire sub base is supportive.
Once the sub base is laid and any soft areas are identified and repaired, it is time to add the binder. Once the supportive structures of a new asphalt surface are installed, the top layer of fresh asphalt is added to provide a clean, smooth ride. It is very rare to install an asphalt surface that does not connect to existing driveways, roadways or parking lots.
As such, asphalt-paving contractors must find a way to smooth the transition from old surface to new. Your asphalt paving contractor should follow these installation steps to make sure your new asphalt surface will provide years of durability and functionally for your home, business, city or town. But remember that installation process should only follow a proper surface inspection and a complete estimate.
Best Practices for Asphalt Overlays and Thin Lifts
Take a look at the articles below that explain those processes completely. With 75 years of asphalt paving experience, from highways to driveways, we are your local source for all of your asphalt paving needs. If you live or work in the Milwaukee area, call us at For the Madison area, call us at Topics: asphalt driveway installationAsphalt Pavement.
Milwaukee: Careers Resources Blog Contact Us. Asphalt Paving Blog. Subscribe to the Wolf Paving Blog. Mrugacz on Sep 28, Step 1: Demolition and Removal The first step in the asphalt installation process is to remove the existing surface, whether it is asphalt, concrete or pavers.
Demolition and removal is completed using heavy machinery, including small bobcats and forklifts and when necessary, front loaders and large dump trucks. Debris is removed and in most instances, Wolf Paving recycles the old asphalt and concrete in our asphalt plantsturning deteriorating waste into strong, usable new asphalt. Step 2: Grading and Sloping With a clean slate, technology helps Wolf Paving asphalt professionals prepare the surface for appropriate water drainage.
Using laser guided transits and automatic motor graders, the Wolf Paving team grades the surface to be paved to ensure that water will run-off appropriately. Proper water drainage is vital to your asphalt, because water is a major cause of damageincluding potholes, cracks and heaving. The sub base provides a stable surface to support new pavement. The sub base is a frost barrier to help reduce winter damage due to freezing and thawing.
During the installation, base thickness, base stability and compaction are important steps. If the sub base is not appropriately compacted, the asphalt surface on top will not provide years of durability. A Wolf Paving proof roll involves driving a quad-axle dump truck, loaded with 72, pounds, row by row over the entire surface. If the gravel flexes more than an inch under the weight of the truck, it means that the base is not properly supported.
Undercutting can be used to repair soft spots. This process involves digging down below the surface 2 or 3 feet and replacing the underlying soft clay or soil with stronger aggregate material.
How a Road is Paved
Wolf Paving also offers alternative options, like using geo-grid, instead of undercutting. Using geo-grid involves digging only 16 inches below the surface and laying grid down to bridge base materials together.During these challenging times, we guarantee we will work tirelessly to support you.
We will continue to give you accurate and timely information throughout the crisis, and we will deliver on our mission — to help everyone in the world learn how to do anything — no matter what. Thank you to our community and to all of our readers who are working to aid others in this time of crisis, and to all of those who are making personal sacrifices for the good of their communities. We will get through this together. A driveway paved with asphalt can last as long as 15 years.
Asphalt is durable, resilient and low-maintenance. The process of paving with asphalt is not difficult, but proper asphalt installation requires heavy equipment that most homeowners do not possess. You might not be able to install asphalt by yourself, but understanding the operation will allow you to ensure that your hired contractor is doing it correctly. Use these steps as an installation guide.
There are 6 references cited in this article, which can be found at the bottom of the page. Explore this Article Steps.Extreme Fast Modern Road Construction Machines, Amazing Asphalt Paving Machine Working
Tips and Warnings. Related Articles. Find a contractor. It's important to feel comfortable with the person you hire. Ask your friends and family for recommendations. You want a contractor who will do a thorough job and who has the best equipment. Have discussions with potential contractors before hiring them.
Study the contract to confirm everything you wish to be done is spelled out in the document. The asphalt will most likely be of poor quality and workmanship. Remove your current driveway surface. This might include breaking up existing concrete and removing the pieces or collecting loose gravel. The surface needs to be completely clean and clear before continuing.
There should no grease or oil stains.