Unless one has remained stoned too long – no pun intended – most people are aware that reclaimed asphalt pavement or RAP has been quite the phenomenon since 1974. Back then, serious efforts were started in Texas & Nevada to test old asphalt to make it sustainable. These days it’s not only pavement that’s recycled; we’ve even found a way to use recycled tire rubber in asphalt binders!
We’ll do you another one: glass for sand!
Of course, recycled asphalt has that ‘dog-eared’ vibe but believe us, it performs even better than fresh asphalt. You can recycle asphalt or add recycled tires for binding and recycled glass for sand in the new asphalt aggregate.
Now, RAP is designed to fulfill three conditions:
- to be environmentally sustainable
- to perform suitably as pavement
- to be cost-effective
The usual method is mixing hot asphalt with recycled asphalt in a heated tumbler truck to pave newer roads; cold mix with recycled asphalt saves energy consumption. We knew the thought might occur to you about using recycled asphalt and recycled rubber (from tires), but according to a study done in 2018, using all-out recycled components only slightly improved the quality of the road but made it too rigid. So far, one recycled component and one new component seems to be the best way to merge materials for sustainable pavement.
Before we drift too far in this great discussion, here are four ways you can recycle asphalt.
- Milling & Chunks:
This involves scraping or milling off the top layer of pavement without removing the subgrade. The chunks of asphalt are trucked to an asphalt recycling plant, where it is crumbled, sorted, and graded for reuse in patch jobs and repairing asphalt.
2. Pulverized Asphalt:
The pavement’s top layer is not milled; rather, it is heated and blended into the subgrade to form a new base for fresh asphalt. This is also called Hot In-Place Recycling. It saves a lot on procuring new subgrade materials, and if need be, can be recycled, then paved with a new binder on top of the blended subgrade.
3. Shred Roof Shingles:
Asphalt shingles are the cheapest option in roofing, and they can last up to 20 years with good care before requiring replacements. The essential ingredients of asphalt shingles include 25-30% asphalt cement, 40-60% hard aggregate, and 3-12% fiber, which are used in hot mix asphalt all the time. Since asphalt shingles can amount to 1.7% of California’s waste disposal (or 1.2 million tons annually according to a Cal Recycle 2018 report), it makes a solid case for shingles to be recycled. After tear-down, the shingles are ground, and their hardness is offset by adding softer asphalt to increase the elasticity required for pavement installation. And then the recycled mix is trucked off to pave away.
4. Glass and Tire Rubber:
While this is not entirely about asphalt recycling, it does involve precise grades of recycled aggregates to form strong pavement. Glass bottles are converted to sand to be used in asphalt. At the same time, rubber tires are recycled into crumbs and binders for pavement. Rubberized asphalt can incorporate some degree of recycled asphalt, but this has to be precise as too much-recycled asphalt can compromise the elasticity of the pavement. Rubberized asphalt is ideal for quiet roads in urban areas.
We hope you gained something new from our bituminous rant about sustainable efforts and everything asphalt. If you require asphalt paving and repair services from advocacy of green paving, then Action Asphalt is the one that will assertively get your pavement up to the mark. Please feel free to consult with us on free and fact-backed quotes, and we will have the best services at your disposal. We are active in Roseville, and the weather is perfect across California for another day to pave!