Asphalt is made by refining crude oil into asphalt binder, then combining that binder with dried, heated stone and sand at an asphalt plant to create the durable pavement used on highways, parking lots, and driveways. For property owners, contractors, and anyone comparing paving options, especially for projects in northern Utah and southern Idaho, understanding how asphalt is made makes it easier to choose the right mix, evaluate installation quality, compare asphalt with concrete, and plan for long-lasting, cost-effective results.
This guide walks through the full process, from crude oil refining and asphalt concrete composition to plant production, mix types, pavement design, sustainability, quality control, installation, and maintenance, so you can better understand what goes into a reliable asphalt surface.
Asphalt, sometimes called bitumen, is a dark brown to black, sticky petroleum product used as a binder. Asphalt concrete (also called asphaltic concrete) is the engineered composite material that combines that binder with aggregates to create the road materials we drive on every day.
Here is what makes up a typical asphalt pavement:
A quick note on terminology: "asphalt binder" or "asphalt cement" refers to the liquid glue, "asphalt concrete" refers to the finished mix, and most people simply say "asphalt" or "blacktop" when talking about the asphalt surface.
Common uses include city streets, interstate highways, airport runways, parking lots, driveways, walking paths, running tracks, and bike lanes. Top Job Asphalt installs and repairs all of these asphalt surfaces across northern Utah and southern Idaho, bringing experience with both residential and commercial asphalt pavements.
Asphalt is made starting at the refinery, where crude oil is heated and separated through fractional distillation. After lighter products separate during distillation, the heavier components left behind become asphalt binder, the essential ingredient in every asphalt pavement mixture.
Here is how the process works. Crude oil enters a distillation tower where it is heated to high temperatures. Lighter petroleum products like gasoline, diesel, jet fuel, and natural gas liquids boil off at progressively higher levels of the tower. The residue at the bottom contains the heavier components, sometimes called vacuum flasher bottoms, and is further processed through vacuum distillation. Bitumen is a thick, black liquid from this crude oil refining process, and it serves as the base for all asphalt binder.
The binder's properties are controlled by adjusting cut points, blending different residues, and sometimes adding polymers to create polymer modified asphalt that meets specific performance grades. For example, PG 64-22 is a common grade selected for local climates in Utah and Idaho, balancing high-temperature rut resistance with low-temperature crack resistance.
Asphalt binder can also be turned into an asphalt emulsion by mixing it with water and surfactants for special applications like tack coats and some cold mix products. Although natural asphalt deposits exist around the world, virtually all modern asphalt pavements in North America use refined asphalt binder from bitumen production for consistent quality.
Asphalt is made like a highly engineered recipe, not a random mix of crushed rocks and oil. Every ingredient serves a specific purpose.
Aggregates form the skeleton of the mix. These include crushed stone, gravel, manufactured sand, and mineral filler. Together, they make up about 90 to 96% of asphalt concrete by weight, depending on the asphalt mix design. Mineral fillers improve the density and moisture resistance of asphalt by filling small voids between larger particles. Fine aggregates and coarse aggregates are proportioned carefully to create a stable aggregate mixture.
Asphalt binder accounts for typically 4 to 6% by weight in dense-graded asphalt mixes. Open-graded or porous asphalt surfaces, which allow water to drain through the pavement, often use higher binder contents. Stone-matrix asphalt provides a strong wearing surface and may use 6 to 7% binder.
Common additives include:
Top Job Asphalt works with modern mix designs tailored to Utah and Idaho traffic and climate, ensuring the right balance of strength, flexibility, and resistance to freeze-thaw cycles.
Here is what happens inside:
Asphalt is made at two main categories of plants: batch plants and drum (continuous) plants.
Batch plants dry aggregates in one drum, then weigh and mix them with binder in discrete batches inside a pugmill. This approach is ideal for frequent asphalt mix changes and smaller production runs. Typical batch sizes range from about 1.5 to 5 tons.
Drum plants handle drying and mixing in a single continuous rotating drum. This allows higher production rates for large paving projects with consistent asphalt mixes. Asphalt plants can produce up to 800 tons per hour with large drum configurations.
|
Feature |
Batch Plant |
Drum (Continuous) Plant |
|
Production mode |
Discrete batches |
Continuous flow |
|
Mix design flexibility |
High, can change batch-by-batch |
Lower, best for large consistent runs |
|
Throughput capacity |
100 to 300 tons/hr |
400 to 800+ tons/hr |
|
Best suited for |
Small jobs, varied specs |
Highways, large commercial projects |
Mobile asphalt plants are also used for remote projects or temporary paving needs, though they are scaled down compared to permanent installations. Regardless of plant type, modern asphalt production is typically automated with computerized controls to ensure temperature, proportioning, and quality are consistent across every ton of asphalt produced.
Asphalt is made into specific families of asphalt mixtures, each with different production temperatures and uses. Choosing the right one depends on traffic loads, climate, project timeline, and environmental factors.
Hot mix asphalt (HMA) is produced at temperatures between 302 and 356 degrees Fahrenheit. Aggregates and binder are both heated to high heat, then placed and compacted while hot. Hot mix asphalt HMA is the standard for highways, major parking lots, and high-traffic asphalt pavements. Properly designed asphalt provides a smooth driving surface with high traction.
Warm mix asphalt uses warm mix asphalt technology such as foaming, chemical additives, or waxes to reduce production temperatures by 50 to 100 degrees Fahrenheit compared to hot mix. This lowers fuel consumption, reduces emissions, and improves workability for paving crews. Warm mix asphalt is produced at lower temperatures while achieving performance close to HMA when properly designed.
Cold mix asphalt can be made without heating the aggregate. It uses asphalt emulsion or cutback binders at ambient temperature, making it ideal for filling potholes, temporary patches, winter pothole repair, and low-traffic areas. Cold mix remains in a semi solid form until compacted in the repair area.
Top Job Asphalt commonly recommends hot mix or high-quality warm mix for long-lasting asphalt surfaces and uses cold mix strategically for fast, stop-gap repairs.
Asphalt is made as part of a layered pavement system, not just a single black layer on top of soil. The flexibility of asphalt allows it to accommodate heavy traffic loads and temperature variations without cracking, but only when the full structure is properly built.
The typical structure includes:
Top Job Asphalt pays particular attention to base preparation and drainage in northern Utah and southern Idaho to prevent frost heaves and premature cracking, which are common when base layers trap moisture through freeze-thaw cycles.
The following table summarizes representative total asphalt thicknesses and base requirements for different asphalt paving applications. Local codes and soil conditions may require adjustments.
|
Application |
Asphalt Concrete Thickness (inches) |
Aggregate Base Thickness (inches) |
Typical Traffic Level |
|
Residential driveway (cars only) |
2 to 3 |
4 to 6 |
Light vehicles |
|
Residential driveway (RVs, trailers) |
3 to 4 |
6 to 8 |
Mixed light and heavy |
|
Small commercial parking lot |
3 to 4.5 |
6 to 10 |
Moderate, delivery trucks |
|
Local residential street (freeze-thaw climate) |
3.5 to 5 |
6 to 12 |
Light to moderate, snow removal |
|
Heavy-duty truck lane / industrial yard |
5 to 8+ |
8 to 12+ |
Very heavy, frequent turning |
Top Job Asphalt designs pavements within or above these ranges based on geotechnical conditions and expected loading, ensuring the final product holds up season after season.
How asphalt is made is only half the story. Continuous quality control at the plant and on the jobsite determines whether the pavement performs as designed.
At the plant, technicians verify:
In the field during asphalt paving, crews and inspectors check:
Performance grading (PG) tests like the dynamic shear rheometer and bending beam rheometer are used at refineries and labs to ensure asphalt binder meets the climate demands of each region. Reputable paving contractors such as Top Job Asphalt rely on proven mix suppliers, trusted labs, and experienced crews to consistently achieve specified densities and ride quality.
Once you understand how asphalt is made, it helps to compare asphalt pavements with concrete pavements when choosing road materials for your project.
|
Factor |
Asphalt Pavement |
Concrete Pavement |
|
Installation speed |
Fast; asphalt pavements can be laid and compacted quickly, allowing them to open to traffic shortly after |
Slower; requires curing time before opening |
|
Initial cost |
Generally lower for comparable thickness |
Higher material and labor cost upfront |
|
Maintenance and repair |
Easier to patch, resurface, and seal coat |
More difficult and expensive to repair seamlessly |
|
Noise and ride comfort |
Quieter, smoother surface |
Can be noisier due to joints |
|
Flexibility in freeze-thaw climates |
Better flexibility, expands and contracts with temperature swings |
More rigid, greater risk of cracking and spalling |
|
Ease of staged repairs |
Simple to mill and overlay sections |
Requires full panel replacement |
Asphalt generally offers faster construction, a quieter ride, easier staged repairs, and better flexibility under Utah and Idaho temperature swings. Top Job Asphalt helps property owners weigh these factors and will typically recommend asphalt where speed, a smooth surface, and maintenance flexibility are priorities.
How asphalt is made today increasingly focuses on sustainability without sacrificing performance. The asphalt industry has made significant strides in reducing waste and conserving resources.
Old asphalt pavements are milled and crushed into reclaimed asphalt pavement, then reintroduced into new asphalt mixes at the asphalt plant to reuse both the aggregates and the asphalt binder. In 2019, new asphalt mixtures contained an average of 21.1% recycled asphalt pavement. Reclaimed asphalt pavement can replace up to 100% of virgin materials in some applications, though modern asphalt production can incorporate up to 50% recycled materials in most standard mixes. Recycled materials can make up to 40% of asphalt mixtures in many state DOT specifications.
WMA accounted for about 40% of U.S. asphalt production in recent years, and that share continues to grow, making the production process more environmentally friendly.
Asphalt production can also utilize recycled plastics and rubber from tires, along with recycled asphalt shingles and industrial byproducts, all of which reduces waste going to landfills. Researchers continue to explore bio based binders as another avenue for environmental considerations. Top Job Asphalt supports sustainable practices where they align with long-term pavement performance.
This table clarifies when to choose each type of asphalt mix based on the production process, typical applications, and trade-offs.
|
Mix Type |
Production Temperature Range |
Typical Uses |
Key Advantages |
Key Limitations |
|
Hot mix asphalt (HMA) |
302 to 356 degrees F (150 to 180 degrees C) |
Highways, major parking lots, high-traffic roads |
High durability, excellent compaction, proven long-term performance |
Higher energy use and emissions; weather-sensitive placement |
|
Warm mix asphalt (WMA) |
50 to 100 degrees F lower than HMA |
Shoulder work, extended hauling, projects seeking energy efficiency |
Lower fuel cost, reduced emissions, improved workability |
Additive cost, potential moisture issues if not controlled |
|
Cold mix asphalt |
Ambient temperature |
Pothole repair, temporary patches, low-traffic or remote areas |
Usable in cold or wet conditions, minimal equipment needed |
Lower strength, shorter service life, not for structural loads |
While cold mix is excellent for quick patches, it is not a substitute for properly designed and compacted hot mix asphalt pavements. Top Job Asphalt primarily relies on engineered hot mix and warm mix for long-term pavements and uses cold mix strategically for temporary fixes.
Making asphalt at the plant is followed by timely trucking, laying, and compaction to create a durable asphalt surface. Every step has to happen within a tight temperature window.
Insulated trucks pick up finished asphalt from silos and deliver it rapidly to the jobsite. The mix must stay within the proper compaction window throughout transport.
At the site, a paving machine spreads the mix at the specified thickness and slope. Automatic grade and slope controls help achieve a smooth surface for road paving and parking lot projects.
Steel drum and pneumatic rollers then compact the asphalt while it is still hot, targeting specific density to achieve long-term durability and resistance to rutting and water intrusion. Proper compaction is the single most important field operation for pavement longevity.
Top Job Asphalt crews are trained to manage timing, temperature, and rolling patterns so that residential driveways, commercial parking lots, and municipal streets open on schedule and perform as designed.
Once property owners know how asphalt is made and installed, a common question is whether to attempt repairs themselves or hire professionals. Here is a side-by-side look.
|
Aspect |
DIY Cold Patch Repair |
Professional Repair by Top Job Asphalt |
|
Material quality |
Cold mix or bagged patch, variable binder content |
Engineered hot mix, proper binder grade, climate-appropriate additives |
|
Base preparation |
Often skipped, patch laid over damaged base |
Full base evaluation, repair, grading, and drainage correction |
|
Compaction equipment |
Hand tamping, limited compaction |
Specialized rollers achieving specified density |
|
Long-term performance |
Short-lived, often fails within months |
Designed for years of service |
|
Appearance |
Rough, patchwork look |
Smooth, uniform asphalt surface |
|
Total lifecycle cost |
Repeated patching adds up quickly |
One quality repair is typically more cost effective over time |
Top Job Asphalt offers proper cut-out and patching, base repair, hot mix replacement, seal coating, and crack sealing that extend pavement life far beyond what simple DIY cold patch can achieve. They provide free, no-pressure estimates in northern Utah and southern Idaho, helping owners decide when full-depth repair or replacement makes more financial sense than repeated patching. Contact them for a free estimate to discuss your situation.
Different asphalt pavement designs come with different cost levels and expected lifespans. This table illustrates relative cost ranges without promising specific prices, since local conditions and material markets vary.
|
Project Type |
Typical Structure (Asphalt / Base) |
Relative Cost Level |
Expected Service Life With Maintenance |
|
Basic residential driveway |
2 to 3 in asphalt / 4 to 6 in base |
Low |
15 to 20 years |
|
Upgraded residential driveway (thicker base) |
3 to 4 in asphalt / 6 to 8 in base |
Low to Medium |
18 to 25 years |
|
Light-duty commercial parking lot |
3 to 4.5 in asphalt / 6 to 10 in base |
Medium |
20 to 25 years |
|
Heavy-duty trucking yard |
5 to 8 in asphalt / 8 to 12+ in base |
High |
20 to 30 years |
Climate, traffic volume, and maintenance practices (seal coating, crack sealing, timely repairs) can shorten or lengthen these ranges significantly. Top Job Asphalt helps customers balance up-front cost against long-term performance by tuning asphalt thickness, base thickness, and mix selection for each unique project.
While the science of how asphalt is made is important, the contractor's workmanship largely determines how long an asphalt surface will last. That is where Top Job Asphalt stands out in the paving industry.
Top Job Asphalt's key strengths include:
Reviews consistently highlight fast response times, clear communication from both office and field crews, careful site prep and cleanup, and projects completed on or ahead of schedule. Their crews use high-quality materials and coatings suited to northern Utah and southern Idaho climates, with attention to proper base preparation and compaction to prevent premature failures.
Visit topjobasphalt.com or contact Top Job Asphalt directly for a free evaluation of your existing asphalt pavements or upcoming asphalt paving projects.
This section covers additional questions that go beyond the main topics discussed above.
Most residential driveways and parking lots paved with hot mix asphalt can handle light vehicle traffic within 24 to 48 hours, although full curing and hardening continues for several weeks. Avoid sharp turns, heavy vehicles, trailers, and parking in the same spot repeatedly for the first 5 to 7 days, especially during hot weather when asphalt remains softer. Top Job Asphalt provides specific reopening guidance for each project based on mix type, thickness, and ambient temperature.
The best paving windows are typically late spring through early fall when daytime temperatures are consistently above about 50 degrees Fahrenheit, allowing adequate compaction and cooling time. Cool, dry weather often produces the best results because the asphalt cools at a manageable rate and moisture in the base layers is minimized. Top Job Asphalt carefully schedules projects around local weather forecasts to avoid rain during paving and early curing.
In many cases, asphalt overlays (new asphalt placed over old asphalt) are possible if the existing pavement is structurally sound and only has surface-level defects. If there are major problems like deep cracking, severe alligator cracking, rutting, or base failures, Top Job Asphalt will usually recommend milling or full-depth replacement instead of a simple overlay. Request a site visit so the team can evaluate whether an overlay, partial reconstruction, or full replacement is the most cost effective solution for your property.
Seal coat is not part of how asphalt is made at the plant. Instead, it acts as a thin protective barrier applied over the finished asphalt surface to slow oxidation and water penetration. Seal coating every 3 to 5 years is recommended for many driveways and parking lots, after the asphalt has cured for at least 3 to 6 months. Top Job Asphalt offers professional seal coating and crack sealing services that complement high-quality asphalt production and installation to maximize pavement life.
Properly designed asphalt mixes using RAP (reclaimed asphalt pavement) can perform as well as or better than all-virgin mixes, as long as binder content, aggregate gradation, and temperatures are controlled. National studies through the FHWA Long-Term Pavement Performance program and decades of field data show recycled asphalt pavements can be extremely durable and cost effective. Top Job Asphalt works with suppliers who follow best practices for incorporating RAP so that customers benefit from both sustainability and long-term performance.