Asphalt Q&A's

What is asphalt?

Asphalt is a mixture of different materials and an oil derivative that is used for paving surfaces.

Asphalt is made with aggregates (different, unrelated materials), binders, and fillers. Common aggregates include the following:

Crushed rock
Sand
Recycled material
Slag (waste that forms when refining ore)
Gravel

There are six steps to making asphalt:

The different aggregates are brought to the manufacturing site and stored in different bins. At this stage, they are generally ambient temperature and damp.
The aggregates are dried and begin to warm.
After they are dried, the aggregates are heated in a very hot elevator.
The aggregates are sorted according to size. Pieces that are too large are removed.
The aggregates are mixed with a filler material and a binder to hold the mixture together.
The asphalt is transported to the work site or to a storage facility.

Bitumen, a substance formed by distilling crude oil, is the most common binder used in asphalt paving. Common fillers include slate dust, cement, and limestone dust.

Asphalt mixes are distinguished by the temperatures they are at installation – hot, warm, and cold. These mixes have various subtypes and each serves a slightly different purpose.

Hot mix asphalt – Is commonly called blacktop and is used on roads, driveways, and parking lots. Common aggregate sizes are ⅜”, ½”, and ¾”
Warm mix asphalt – A newer, more environmentally friendly approach to paving
Cold mix asphalt – Used for temporary repairs in low-traffic areas

What is Asphalt Removal and Replacement?

Removal and replacement consists of removing and disposing of the existing asphalt and repaving the area with new asphalt. Typically, a removal and replacement is necessary when an asphalt surface has failed beyond the point where it can be salvaged. It is not uncommon to replace and compact the base material below the asphalt at that time if the foundation is unstable. L&S Paving specializes in removal and replacement using only the highest quality material to complete your project.

When can you repair asphalt?

When asphalt needs to be repaired, it generally only requires surface work since the lower layers are pretty much permanent. This (generally) makes repairs simple. It’s also possible to blend repaired asphalt with the rest of the paved area. With concrete, however, repairs are difficult and are easily visible. If the damage is extensive, the entire slab will need to be repoured.

What are the different types of asphalt repairs?

1. ASPHALT PATCHING

Asphalt patching is the process of placing one to two inches of hot asphalt over damaged areas of your pavement. Patching your surface with asphalt is a very versatile solution to fixing many types of surface problems. It is especially useful in high traffic areas for parking lot repair and drainage problems. Asphalt patching is best for customers who need a cost-effective solution for fixing minimally-damaged areas of their pavement.

2. ASPHALT REMOVAL AND REPLACEMENT

Asphalt removal and replacement (also known as peeling and paving) could be the best asphalt repair solution if you are looking for long-lasting results. This method is required when simple patching and overlays are not enough to fix your pavement. The removal and replacement process is done by removing existing asphalt and then installing new asphalt to correct pavement damage.

3. ASPHALT RESURFACING

Asphalt resurfacing is best for fixing large portions of your pavement with extensive damage. Resurfacing your pavement is done by adding a new layer of asphalt to your existing layer. This method will repair cracks and improve your pavement’s overall look. Asphalt resurfacing is one of the most cost-effective solutions for increasing the life of your asphalt.

4. COLD MILLING

Cold milling machines are designed to quickly remove asphalt and concrete surfaces to create a foundation for paving new surfaces. Milling machines are great options for repair work on large areas. Due to their sufficient size and self-propelled structure, milling machines have become common in construction for removing and repairing asphalt pavements.

What is the asphalt paving process?

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 then removed. we recycle the old asphalt and concrete in our asphalt plants, turning deteriorating waste into strong, usable new asphalt. In fact, L&S typically recycles nearly 100% of the materials removed from a job site, making the choice to use L&S both green and environmentally friendly.

Step 2: Grading and Sloping

With a clean slate, technology helps L&S professionals prepare the surface for appropriate water drainage. Using laser-guided transits and automatic motor graders, the L&S 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 damage, including potholes, cracks, and heaving.

Step 3: Prepare the Sub Base

You’d never guess that the most important part of your new asphalt surface is actually the sub base. 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 essential steps. If the sub base is not appropriately compacted, the asphalt surface on top will not provide years of durability.

Step 4: Proof Roll, Undercutting and Sub Base Repair

Once the sub base is fully graded and compacted, L&S completes an extra step, called a proof roll, to ensure the underlying surface is strong and ready to support new asphalt. A L&S Paving proof roll involves driving a quad-axle dump truck, loaded with 72,000 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. If the proof roll finds soft areas in the sub base, L&S Paving makes the necessary repairs in compromised areas to ensure the entire sub base is supportive. 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. L&S 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. This creates a solid support structure for new asphalt at a fraction of the cost of traditional undercutting. L&S has also pioneered a new process called plowing. This process involves undercutting the sub base, but instead of removing all of the soft clay and soil, it is instead mixed with added aggregate to improve the strength of the compromised areas.

Step 5: Binder and Surface Course

Once the sub base is laid and any soft areas are identified and repaired, it is time to add the binder. The binder layer is large aggregate mixed with oil, making it very strong and durable. The binder layer can be thought of as the strength of any new asphalt surface.

Step 6: Install New Asphalt Surface

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.

Surface asphalt is made up of small aggregate, sand, and oil.
This combination of materials creates jet-black asphalt that, when installed appropriately, provides a smooth ride and a shiny, attractive finished surface.

Step 7: Butt Joints and Transitions

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.

Butt joints are areas where old asphalt or concrete meets new asphalt pavement.
These transitional areas require special attention to ensure that the grading and water run-off is appropriate.
Butt joints are important to ensure drivers and pedestrians don’t notice a difference in the surfaces.

To Complete the Project: Final Roll

Once the asphalt and butt joints have been laid, the entire surface is smoothed and compacted.

Using a roller truck, the new asphalt pavement surface is compacted and smoothed.
This process step ensures that no small bumps of aggregate or stone are left poking through the smooth new surface.

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.

If you have any questions, feel free to reach out!

(951) 456-9179

Jurupa Valley, CA 91752

lsgradingpaving.com