Can Asphalt Be Recycled? The Surprising Truth About Reusing Roads
Published on: September 30, 2025 | Last Updated: April 14, 2025
Written By: George Voss
Yes, asphalt ranks among the most recycled materials in the US—over 95% gets reused. Made of crushed stone (aggregates) and sticky petroleum binder (bitumen), old roads and driveways become Reclaimed Asphalt Pavement (RAP). RAP gets crushed, heated, and blended with fresh bitumen to create new pavement. This process reduces CO2 emissions by 20% compared to virgin asphalt and cuts costs by up to 30%.
This guide explores how asphalt recycling works. You’ll learn about hot in-place recycling (repaving roads on-site), cold recycling (mixing RAP at lower temps), and DIY options for driveways. We break down cost savings per ton ($15-$30 vs $50-$80 for new asphalt), environmental impacts, and limitations like max reuse rates (40% RAP in highways). Compare recycled asphalt to gravel, find recycling facilities, and get answers to top disposal questions.
Contents
What is Asphalt?
This dark, sticky substance binds stone, sand, and gravel to form paved surfaces. Bitumen, the binding agent derived from crude oil, gives it flexibility under temperature shifts. You’ll find it under tires on highways, beneath feet on walkways, and supporting vehicles in parking lots.
Composition and Common Uses
Modern mixes contain 90-95% stone or sand plus 5-10% bitumen. Specific blends vary based on needs: high-traffic roads use stiffer bitumen graded PG 64-22 (Performance Grade), while driveways get softer PG 58-28. Over 94% of paved roads in the U.S. use this material due to its smooth finish, quick installation, and noise reduction.
Why It Dominates Pavement Materials
Bitumen’s thermoplastic nature allows reheating without breaking down—the core reason recycling works. Unlike concrete, which cracks under stress, it flexes under heavy loads. The U.S. reuses 95% of milled pavement yearly, saving $2.5 billion in material costs. New mixes now integrate up to 50% reclaimed material (RAP) without compromising strength. This closed-loop system cuts mining needs by 60 million tons annually.
These qualities set the stage for exploring how recycling works in practice.
Is Asphalt Recyclable?
Yes. Asphalt ranks as the top reused stuff in the U.S. Each year, 95% of old roads get a new life. This high rate stems from its core traits.
Key Properties That Enable Recycling
Asphalt mixes rock, sand, and a black glue (bitumen). Heat softens bitumen. This lets old chunks bond with new mix. Rock and sand stay strong through many uses. RAP (old asphalt chunks) keeps these traits intact. Tests show RAP works as well as new mix in most cases.
Can Asphalt Be Fully Reused or Repurposed?
Old asphalt can’t be 100% reused. But up to half can go into new roads. It’s also crushed for gravel, base layers, or patches. Some plants take up to 80% RAP for low-stress jobs like parking lots.
| Common Uses of RAP | RAP Used |
|---|---|
| New Roads | 30-50% |
| Driveway Gravel | 100% |
| Base Layers | 60-80% |
Dirt, oil, or trash in old mix can limit reuse. Plants test RAP to ensure it meets specs like gradation and binder content.
Next, let’s break down how this process works step by step.
Thе Asphalt Rеcycling Procеss
Turning old pavеmеnt into nеw surfacеs rеquirеs a systеmatic approach. Thе four-stagе systеm transforms wastе into a functional product, maintaining structural intеgrity whilе cutting costs.
Stеp 1: Collеction and Transportation
Workеrs first rеmovе dаmаgеd or agеd asphalt using milling machinеs or еxcavators. Trucks haul matеrial to rеcycling cеntеrs, with typicаl hauling costs ranging from $12-$30 pеr ton basеd on distancе.
Sourcеs of Rеclaimеd Asphalt Pavеmеnt (RAP)
RAP comеs from roads, parking lots, driveways, or construction dеbris. Highway rеsurfacing projеcts supply 85% of RAP, whilе rеsidеntial rеnovations contributе 10-15%. Somе statеs mandatе at lеast 30% RAP in nеw road builds.
Stеp 2: Crushing and Scrееning
Jaw crushеrs or impact mills brеak RAP into 0.5”-1.5” piеcеs. Scrееning sеparatеs chunks by sizе—largеr piеcеs work for basе layеrs, finеr matеrial suits surfacе coursеs. Modеrn plants procеss up to 600 tons pеr hour.
Stеp 3: Removing Contaminants
Magnеtic sеparators pull out mеtal fragments, whilе vibratory dеcks sift rocks or soil. Plants discard up to 5% of incoming RAP duе to pollution from oil, wood, or plastic. High-gradе RAP has lеss than 0.5% forеign matеrial.
Stеp 4: Blеnding With Frеsh Matеrials
RAP combinеs with nеw aggrеgatеs and bindеrs likе PG 64-22 bitumеn. Mixеs contain 10-50% rеcyclеd contеnt, dеpеnding on cliмате and traffic loads. Supеrpavе tеsts еnsurе thе blеnd mееts spеcs for rigidity (300-800 MPa) and moisturе rеsistancе.
With thе procеss clеar, lеt’s analyzе diffеrеnt tеchniquеs to apply rеcyclеd asphalt in rеal-world sеttings.
Also See: Best Practices for Maintaining Asphalt Quality
Methods Of Recycling Asphalt
Recycling asphalt uses advanced techniques to transform old pavement into reusable material. Three primary methods handle different project scales and budgets.
Hot In-place Recycling
Hot in-place recycling (HIR) reuses asphalt directly on-site. Crews heat the existing pavement to 300-350°F, soften it, and mill 2-3 inches of depth. The reclaimed asphalt pavement (RAP) is mixed with fresh binder or rejuvenators like PG 64-22 asphalt cement. This method repairs surface cracks in 4-8 hours, costs 20-30% less than full-depth replacement, and works for highways or arterial roads.
Cold Central Plant Recycling
Cold central plant recycling processes RAP off-site. Milled asphalt is crushed to 0.5-inch minus aggregate, blended with emulsified asphalt or foamed bitumen (3-5% new binder), and compacted. The mix cures for 1-3 days before traffic use. This method handles up to 100% RAP content, cuts material costs by 30-50%, and suits parking lots or rural roads. ASTM D6626 standards ensure quality control for load-bearing layers.
Can You Recycle Asphalt at Home?
Homeowners can’t fully recycle asphalt without industrial equipment. DIYers break old driveways into 12-inch chunks using jackhammers, then haul them to recycling centers. Processing fees range $10-$30 per ton. Some facilities accept asphalt shingles (tear-offs must contain ≤3% contaminants) but process them separately from pavement. Never burn asphalt—toxic fumes release benzene and sulfur compounds.
These methods prove asphalt pavement recycling works at any scale. Next, explore how reused material benefits budgets and ecosystems.
Benefits Of Recycled Asphalt
Recycled asphalt offers two main perks: lower costs and a cleaner planet. Both builders and towns gain from its reuse.
Reduced Material Costs
Recycled asphalt cuts costs by 20-30% versus new mix. Up to 30% RAP can be used in fresh batches. Less new rock, sand, and bitumen are needed. Haul fees drop as old pave is reused on-site. Some states offer tax breaks for using RAP.
Lower Environmental Footprint
Recycled asphalt slashes harm to the planet. Reuse cuts the need to mine new rock and sand. This saves land and cuts CO2 by up to 21 million tons each year. It also uses 50% less energy than making new mix. Jobs that use 30% RAP earn LEED points for green builds.
While the perks are clear, recycled asphalt has some limits to weigh.
Limitations Of Recycled Asphalt
While asphalt recycling cuts costs by up to 30% and diverts 100 million tons of material from landfills annually, its use has boundaries. Knowing constraints guarantees optimal outcomes for paving projects.
Quality Control Challenges
RAP (Reclaimed Asphalt Pavement) quality varies by origin. Aged binders lose viscosity, and aggregate gradation shifts with prior traffic loads. Contaminants like dirt or roofing shingles—common in stockpiles—can drop mix integrity by 15% if exceeding 0.5% content limits.
| Contaminant Type | Max Allowable Content |
|---|---|
| Organic matter | 0.5% |
| Metals | 0.1% |
| Plastics | 0.3% |
PG binders (Performance-Graded) in fresh asphalt must compensate for aged bitumen stiffness. Without strict lab testing per AASHTO M 323 standards, recycled mixes risk premature rutting or cracking.
Applications With Performance Constraints
High-traffic zones like interstate highways or ports demand mixes with ≤15% RAP. Truck loads above 40,000 lbs. daily strain pavements, requiring virgin binder ratios of 85% or higher. Airport runways, subject to jet fuel exposure, rarely permit RAP due to thermal stress risks.
- Heavy industrial sites: Limit RAP to 20% for stability
- Cold climates: Avoid >25% RAP to prevent thermal cracking below -20°F
- Steep slopes: Fresh asphalt improves shear strength by 40% vs. recycled
Beyond physical limits, comparing how recycled asphalt stacks up against alternatives like gravel informs smarter material choices.
Recycled Asphalt Vs. Gravel
When picking between recycled asphalt and gravel, cost, strength, and use cases matter. Both serve unique roles in paving jobs.
Cost and Durability Comparison
Recycled asphalt costs $10-$20 per ton. Gravel runs $15-$40 per ton. While gravel seems cheap at first, recycled asphalt lasts longer. It holds up for 15-20 years vs. gravel’s 5-10 years. The bitumen in old asphalt rebinds during recycling, making it stick like new. Gravel shifts and breaks down faster, needing more upkeep.
- Recycled asphalt: Saves up to 50% vs. new asphalt
- Gravel: Costs rise with frequent grading and refills
Best Use Cases for Each Material
Pick recycled asphalt for high-traffic zones. Use gravel where water flow or low use is key.
- Recycled asphalt: Roads, driveways, parking lots. Handles heavy loads without rutting.
- Gravel: Drainage ditches, rural paths, temp access roads. Lets rain soak through fast.
For green jobs, recycled asphalt cuts waste. Gravel works where budgets are tight or soil needs to breathe. Both can be reused, but asphalt pavement recycling offers more long-term value.
Choosing the right mix depends on your site needs. Next, let’s explore how to dispose of old asphalt the right way.
Responsible Asphalt Disposal Options
When old pavement needs replacement, recycling keeps it out of landfills. Over 90% of reclaimed asphalt pavement (RAP) gets reused in new projects. Proper disposal methods protect ecosystems while supporting sustainable construction practices.
Locating Recycling Facilities
Finding centers that process RAP takes minimal effort. Use tools like Earth911’s database or contact local construction material suppliers. Many state transportation departments list approved facilities online. Certain plants specialize in cold central plant recycling, while others handle hot in-place methods. Verify accepted materials before hauling to avoid rejection.
Preparing Asphalt for Recycling
Proper prep work ensures smooth processing. Follow these steps:
| Step | Requirements | Tools Needed |
|---|---|---|
| Breaking Down | Pieces under 24 inches | Jackhammer, loader |
| Cleaning | Remove dirt, concrete, debris | Pressure washer, hand tools |
| Storage | Keep dry until transport | Tarps, pallets |
Most centers reject loads with over 5% contamination. Check if the facility requires testing for petroleum residues or other pollutants.
Frequent questions on recycling practices surface when planning pavement projects.
Frequently Asked Questions (FAQs)
Is Asphalt a Recyclable Material?
Yes, asphalt is highly recyclable. Approximately 95% of asphalt pavement is reused in new construction and maintenance projects each year in the United States.
Can Asphalt Be Melted and Reused?
While asphalt cannot be melted in the same way as some other materials, it can be heated and reworked. During the recycling process, heat is applied to soften the existing asphalt, allowing it to be integrated with new materials.
What is the Best Way to Dispose Of Asphalt?
The best way to dispose of asphalt is to take it to a specialized recycling facility. Many local recycling centers accept asphalt for reuse in new projects, ensuring that it doesn’t end up in a landfill.
How Durable is Recycled Asphalt?
Recycled asphalt is comparably durable to new asphalt. It can provide a service life of 15-20 years, depending on the application and mix used. Proper blending and quality control during processing are crucial to maintaining its strength and longevity.
Are There Free Asphalt Recycling Programs?
Some local municipalities or counties offer free or low-cost asphalt recycling programs for residents. It’s advisable to check with local government or recycling centers for availability and any potential fees.
Can Asphalt Shingles Be Recycled With Pavement?
Ashphalt shingles can indeed be recycled together with pavement, but they usually undergo separate processing due to different material properties. Therefore, facilities commonly handle asphalt shingles specifically, ensuring they meet contaminant standards.
Final Words
Asphalt recycling is not just feasible; it’s a vital part of sustainable construction practices. This process significantly reduces waste while conserving natural resources. With methods like hot in-place and cold central plant recycling, reclaimed asphalt can be effectively reused, providing cost savings and a lower environmental footprint. Despite some challenges in quality control, the benefits often outweigh the limitations.
For more details about asphalt recycling and its advantages, be sure to check out Asphalt Calculator USA. Together, we can contribute to a more sustainable future while paving the way for smarter construction solutions.
Additional Resources for You:
- Kett, I. (1999). Asphalt Materials and Mix Design Manual. Oxford: Elsevier Science.
- Can existing asphalt be reused for paving a new road, or does it have to be removed completely before fresh material can be laid down? – Quora
- Recycling – National Asphalt Pavement Association
- r/asphalt on Reddit: Pros and Cons of Recycled Asphalt
- How to Recycle Asphalt – RecycleNation
