Asphalt paving is essential to everyday life, so it’s no surprise that asphalt pavers are seen working on countless highways and streets. But how does a paver work? What makes them such an effective tool in the construction industry? In this blog, we’ll explore what precisely an asphalt paver is and how it works to ensure roads stay sturdy and safe for travel.
We’ll also look at some of the features that have made these machines indispensable in modern engineering projects. So if you’re wondering what goes into ensuring our roadways last through rain or shine, read ahead to learn more.
Asphalt Paving Process
The asphalt paving process involves several steps, including grading and preparing the surface, applying a base and binder layer, and finally, adding the top layer of asphalt. It takes skilled workers, specialized equipment, and attention to detail to ensure a successful, long-lasting paved surface.
One key component of this process is using an asphalt paver, which ensures an even and precise application of the asphalt. Without it, the paving process would be much less efficient and could result in an uneven and unsafe surface.
Components of an Asphalt Paver
An asphalt paver is an essential piece of equipment used in road construction that plays a crucial role in applying asphalt on roads, highways, and parking lots. Here are the main components of an asphalt paver and their functions:
Hopper – This is a large container located at the front of the paver where the asphalt mix is stored before it is moved by the conveyor chains to the screed. Hydraulically folding hopper wings located on either side make room for dump trucks and increase hopper capacity. They fold in to deliver the last bit of asphalt to the conveyor and make a smaller package for transport. The open design allows the asphalt truck to empty its contents directly into the paver’s hopper.
Conveyor System – The conveyor system transfers the asphalt mix from the hopper to the screed. The conveyor consists of a series of heavy-duty chains and flight bars that move the material at a constant speed. Operation is usually handled by an automatic feed control system such as cut off paddles or switches.
Screed – This is the most critical component of the asphalt paver because it determines the smoothness and uniformity of the final pavement. The screed is pulled by a screed arm located on each side of the paver. The screed plate is responsible for spreading the asphalt mix evenly over the surface, and it’s adjustable to allow for different material depths, widths, and grades.
Augers – These screw-like components are located at the rear of the conveyor in front of the screed and control the amount of asphalt mix delivered to the screed extensions. Augers help to ensure that the head of material is uniform and level across the screed’s entire width. On wide conveyor pavers augers do not need to be used when paving at standard paving width.
Types of Asphalt Pavers
Asphalt pavers come in different types depending on the type of work they are suitable for. Here are the main types of asphalt pavers and their advantages:
1. Tracked Pavers – These pavers are designed for large road construction projects that require high precision and efficiency. They are powered by tracks, providing better traction and stability on unimproved surfaces than wheeled pavers. Tracked pavers are also suitable for working on steeper slopes and soft surfaces.
2. Wheeled Pavers – These pavers are suitable for road construction and maintenance projects on improved surfaces that require flexibility and ease of movement. They are powered by wheels, which makes them more mobile than tracked pavers. Also, wheeled pavers can be driven faster on public highways, making them ideal for road maintenance work.
3. Asphalt Pavers with Bolt-On Screed Extensions – These pavers have screeds that can be extended horizontally. This extension creates wider screeds, which leads to increased paving widths. They are ideal for large road construction projects that require wide paved areas like airport runways or bus stations.
4. Mini Pavers – These are small and suitable for paving narrow, tight spaces. Primarily you will see them used to pave behind a milling machine since their tracks can fit inside a 4ft milling cut. They are also perfect for small repair projects like patches, bike lanes, cart paths, and parking lots. Mini pavers are also highly maneuverable and can work in areas with limited access.
Preparing the Surface for Paving
Before paving a new surface, it’s essential to ensure you’ve adequately prepared the area to prevent any future problems. Properly preparing the surface is critical because if you don’t, it can result in a subpar finish and could even cause the pavement to start cracking and breaking apart after just a short time.
The best way to prepare the area is by following specific steps, including cleaning the surface, removing debris or objects, and fixing any issues such as tire ruts, potholes, or cracks. Think of it like cooking a meal – if you don’t follow the recipe correctly, you’ll end up with an unappetizing dish.
Placing and Spreading Asphalt
Laying asphalt involves using an asphalt paver, a machine designed to spread the material evenly and smoothly over the surface. The paver delivers material to the screed evenly to ensure it flows well and adheres to the base layer. The operator controls the speed and direction of the paver to ensure the asphalt is spread consistently.
Proper placement and spreading are crucial to ensure that the road or pavement is level and has maximum durability. Uneven or lumpy areas can cause water accumulation, leading to damage and potholes.
Compacting the Asphalt
Compacting the asphalt ensures that it is appropriately integrated and tightly packed, creating a smooth, durable surface resistant to water, cracks, and potholes. Different types of compactors are used in asphalt paving, and each has unique advantages. Vibratory rollers, for instance, are suitable for compacting the newly laid mat. Pneumatic tire rollers that use only tires contribute to the final finish of the last layer by improving its density, reducing voids, and perfecting the finish.
Maintaining the Asphalt Paver
Maintaining an asphalt paver is crucial to ensuring its longevity and efficiency. Proper maintenance saves you money on repairs down the line and keeps your equipment running smoothly, which translates to better performance on the job.
Some of the essential maintenance tasks for your asphalt paver include removing asphalt buildup, lubricating moving parts, monitoring hydraulic and electrical systems, cleaning and inspecting filters, and checking the condition of the screed plates. Inspection and cleaning of the paver’s crawler tracks and hydraulic drives regularly. Regular inspection, servicing, and repair of your asphalt paver helps prevent breakdowns, extends the lifespan of the equipment, and ultimately enhances your productivity.
Troubleshooting Common Issues
As with any equipment, asphalt pavers can experience different issues during operation. However, here are some common issues and steps to troubleshoot them:
Uneven Asphalt Surface
Uneven asphalt surfaces can be caused by excessive screed angle-of-attack adjustment, improper or uneven head of material, or inconsistent paving speed. To fix these issues, wait multiple paver lengths between angle-of-attack adjustments, adjust conveyor and auger speeds to even head of material, and maintain a consistent paving speed. Use of automatic screed control systems (also called automatic grade control) can help you maintain a consistent grade. These systems can also control slope using slope sensors mounted on the screed.
Low Pavement Density
Low pavement density can be caused by insufficient compaction, incorrect material gradation, and incorrect temperature. To fix this issue, increase compaction efforts, ensure the correct material gradation, and check that the asphalt in your dump truck is at the correct temperature.
Poor Asphalt Mat Finish
Poor asphalt mat finish can occur due to insufficient screed heat, insufficient screed vibration, incorrect material temperature, low quality asphalt mixtures, and incorrect tractor and screed settings. To fix this issue, increase screed temperature, check material temperature in dump truck, turn on screed vibrator, and adjust equipment settings. It could be necessary to have a qualified technician perform screed leveling to get your machine back to factory adjustment.
Segregation occurs when the different materials in the asphalt mix separate. This issue can be caused by improper mix design, incorrect handling of the combination, or incorrect equipment settings. To fix this issue, redesign the asphalt mix, ensure proper mix handling, and adjust the equipment settings.
Conveyor issues can be caused by material build-up in the hopper or conveyor plates, incorrect chain tension, and insufficient lubrication. To fix this issue, clean the hopper and conveyor chains, adjust chain tension, and properly lubricate the equipment.
Safety precautions, including asphalt paving, are crucial when working on any construction project. These precautions help to reduce the risk of accidents, injuries, and fatalities. Here are some of the safety gear and equipment required for asphalt paving:
- Personal Protective Equipment (PPE) – Safety vests, hard hats, long sleeve shirts, long work pants, safety glasses, steel-toe boots, and gloves are some of the essential protective gear your company may specify for workers when asphalt paving.
- Traffic Control Devices – include cones, barricades, and signs to alert pedestrians and drivers of ongoing construction work and avoid accidents.
- First Aid Equipment – A first aid kit should be available on the job site and easily accessible in an emergency.
- Fire Extinguishers – Fire extinguishers should be placed in strategic locations on the job site.
- Equipment Safety Features – Asphalt pavers should have all safety features in good working order such as backup alarms, warning decals, and flashing beacon lights. Operations & Service manual should be kept with the machine for reference.
- Training – Workers should receive appropriate training from their company on operating equipment, using safety gear, following the Operations & Service Manual, and identifying other potential jobsite hazards.
Benefits of Using an Asphalt Paver
Using an asphalt paver offers many benefits that other paving methods cannot compare to. One of the most notable is the durability and longevity it provides. Asphalt has been known to last 20 years or more with proper maintenance, making it a cost-effective choice in the long run.
In addition to its durability, the smooth surface it creates is also a significant advantage, as it allows for better traction and improved ride quality. Furthermore, compared to other methods like concrete or gravel, asphalt pavers are quicker to set up and complete, leading to less traffic disruption and faster project completion.
Asphalt paving equipment’s impact on the environment can be minimized. Tier 4 Final diesel engines reduce NOx emissions using DEF fluid injected into the exhaust SCR. These same Tier 4 Final engines reduce particulate matter by trapping them in the DPF or diesel particulate filter. Unburned hydrocarbons are minimized by the DOC or diesel oxidation catalyst. Older tiered engines with none of these emissions control components should be kept in good running condition so they will perform at their highest efficiency. Consider shutting off your engines when waiting on more trucks or during other breaks in production.
Future of Asphalt Paving
The future of asphalt paving looks promising as emerging technologies and advancements continue to improve the industry. Recent developments include using recycled materials, new binding agents, and advanced equipment that makes the process more efficient and environmentally friendly.
Understanding how an asphalt paver works and the components involved in the process can help you appreciate the complexity of this vital task. Whether you’re a construction professional or simply interested in learning more, knowing about the advancements in the industry can be beneficial.
If you’re looking for high-quality tools and equipment for your asphalt paving needs, consider checking out LeeBoy. We are a reliable partner for your paving needs with a wide range of products and services. Don’t hesitate to contact us for any questions or assistance with your paving projects.