How Does An Asphalt Paver Work?

Most people are confused between a screed and a paver. They believe that the whole machine that lays down the asphalt is known as the screed, which is incorrect. The whole machine is called an asphalt paver and the screed is an important component of that machine. In this article we will discuss what are the types of pavers, How Does Asphalt Paver Work, what are the components, and what role each component plays in the paving process.

Asphalt paving is regarded as a challenging task that requires accuracy and appropriate mix designs. Paving specialists don’t truly consider the potential for error when they are hired to pave asphalt. But mistakes are made, and this is apparent with time. It will be too late to make things right by then. Selecting a trustworthy paving expert is therefore essential if you want to produce superior outcomes. The most typical issues with asphalt pavement are listed below, along with solutions.

Types Of Asphalt Pavers

Wheeled Pavers

The most common pavers that we see are wheeled pavers. These are ideal for small and medium-sized projects and are especially common in maintenance works. Their mobility due to their wheels, allows easy and fast traveling over urban environments where there is a good road network.

Tracked Pavers

These pavers use tracks similar to tanks but smaller in size. These tracked pavers are mostly used in large projects like paving highways. They can easily maneuver in difficult terrains and areas where the ground is uneven and brittle. These are slow but are very useful for heavy-duty asphalt paving services.

Pavers That Use Bolt-On Screed Extensions

These pavers operate the same way as normal pavers but have a specialized screed that can extend horizontally. This helps in covering a larger area at a time while retaining a compact frame during transportation. These are often used in airport pavements and spacious areas.

Mini Pavers

As the name suggests, these are smaller versions of the average pavers that we are used to seeing and are used to pave confined and hard-to-reach areas. They are relatively mobile, easy to operate, and also cost-efficient.

Components Of An Asphalt Paver And Their Role In The Pavement Process

1. Tractor

The tractor is what drives the whole paver forward. It consists of the basic components that a normal tractor has like transmissions, gearbox, engine, brakes, etc. A powerful and well-functioning tractor is very important as it helps in maintaining a constant speed during the pavement process. Speed is very important while laying down the aggregate. The aggregate has to be poured at the right temperature, with the right flow, and with the right thickness. An issue in the transmission or the gearbox can result in fluctuating speeds which can result in unleveled pavement. The engine has to be well maintained on a regular basis and checked before the job as it can cause financial losses and stop the whole process in case of any malfunctions, or stoppages.

2. Hopper

A hopper is a large compartment located in the front of a paver. It’s like a huge bucket with folding walls. It receives all the aggregate material from the trucks and holds it to ensure a continuous, uninterrupted supply of material.

Continuous supply is important because if there’s a break in the pavement, it can result in cracks in the future and also won’t result in a seamless pavement. Even a small break can result in a temperature difference between the already-laid material and the newly-filled material. Hoppers solve this problem by holding massive amounts of materials at a time and feeding the paver continuously. Read more about: Asphalt Paving Process

These hoppers have folding sides which can expand to provide a larger area for the trucks to unload the material. It eases up the process for the truck drivers and helps them in unloading the fresh aggregate material into the hopper. These sides then can fold towards the inside to make sure that all the material is slipped into the machine, resulting in zero wastage.

3. Conveyor

Conveyor belts are placed below or just at the tip of the hopper. These conveyors transport the material from the hopper to the augers at a constant speed, helping in achieving a continuous supply of material.

4. Augers

Augers are giant rotating blades that continuously rotate and evenly distribute the material, they receive from the conveyor. The blade design is similar to that of a crock screw but with a lot wider blades for maximum surface area. A motor rotates the blades and they keep leveling the material so that it can be fed into the screed. There are often 2 separate augers for each side of the paver.

Augers are responsible for providing an ideal “Head of material”. Head of material is a term used to describe the amount of material that is pushed right in front of the screed, which then levels it out. The right amount of head of material is crucial as almost 95% of material issues during paving, occur due to an inconsistent amount of material being pushed to the screed. A fluctuating supply will result in a lower-quality road or pavement. If the supply is more, it will result in a wavy pavement due to the increased friction between the surface and the screed. If the supply is insufficient, it will result in a thin surface, which will drastically affect the overall strength and durability of the pavement.

The proper functioning of augers will help in getting more consistent and quality results.

5. Screed

Screed is what levels out the material evenly on the surface. This is the place just below where the screed operator stands. The head of the material discussed above is placed in front of the screen. It takes the material and spreads it evenly while also maintaining the desired thickness.

The thickness is achieved by maintaining an optimal angle of attack. The angle of attack is the angle at which the screed hits the material and slopes it out. In simpler words, it’s the angle of the slope which can be changed to achieve the desired thickness. It is controlled by a handle or a lever, also known as a “thickness control screw”. A perfect angle is when it gives the perfect thickness with no extra friction. The screed is made up of metal and has to come in direct contact with the hot material. That is why the screed has to be preheated to match the temperature of the material. Otherwise, it can lower the temperature of the material, which is not a good thing.

Conclusion

An asphalt paver is a complex machine that is a staple in providing Asphalt Maintenance Services. It is an invention that has helped in the speedy development and repair of asphalt roads, pavements, and parking lots. Understanding all the above processes, components, and their importance will help develop a better understanding of how an asphalt project is executed.