[lucasmullens]

> 99 percent of reclaimed asphalt pavement being put back to use

Can't that be interpreted as them just not reclaiming asphalt they can't reuse? Genuinely asking, since things like this are often optimally worded for good publicity.

[snapplebobapple]

I think maybe some of the confusion is over how asphalt works. It's really easy to reclaim because it is essentially just a phase change operation. I forget the exact temperatures but you heat asphalt up past a certain point and it turns into basically a slurry of whatever hydrocarbon (plus additives) that is doing the phase change and stuff like sand, small stone, etc. The sand and small stone is infinitely reusable so when they resurface they are often scraping up the old, loading it into a machine that heats it up, adds a small amount of the hydrocarbon (and additives) plus some more filler (think sand) and putting it right back down to cool down and solidify.

Cement is a chemical process that can't be easily undone so once you use cement you are hooped, very limited recycling options other than grind it up and use it as filler in the new batch.

[traviswt]

The alternative to reclaiming would be to leave it in place and pave over the top (asphalt overlay). That has limits, though, so reclamation will be a requirement over time.

The claim and wording is valid and correct, though. You cannot recycle asphalt if you leave it in place. And what is removed is recycled at a rate of 99%.

If you don't reclaim the asphalt, then it's still in place, and technically still in use.

[maicro]

Fair point, and I don't have enough background to really answer that. I'll look for any information on "reclamation" rates of asphalt - there's got to be some amount that's just lost in general (ground up into fine particles that blow away, fall into drainage systems, etc.), and places where it's just not reasonable to tear it up to bring to a recycler vs. dump it somewhere convenient, but it does _sound_ like they are pretty good about reclaiming and recycling it.

The next chunk in the abstract I quoted is:

"The average percentage of RAP used in asphalt mixtures has increased from 15.6 percent in 2009 to 21.1 percent in 2019. In 2019, the estimated RAP tonnage used in asphalt mixtures was 89.2 million tons. This represents 4.5 million tons (24 million barrels) of asphalt binder conserved, along with the replacement of more than 84 million tons of virgin aggregate."

That gives some context as to how much is actually being reused.