Asphalt pavement: America’s Number 1 recycled product.
By Christine Knable
As early as 1993, asphalt pavement was identified as America’s most recycled product. According to the Federal Highway Administration and the U.S. Environmental Protection Agency, approximately 80 million tons of asphalt pavement are reclaimed each year, and nearly 100% of that total is recycled.
Recycling is defined as converting waste into reusable material or to use again and the act of recycling can contribute to sustainability, which is the avoidance of the depletion of natural resources in order to maintain an ecological balance. Today’s global citizens recycle and reuse everything from paper products to rubber tires to plastics but the most recycled product in America is asphalt, according to napa.com, making parking lots a key contributor to sustainability goals.
Starting with the basics, asphalt pavement is made up of 95% aggregate and 5% binder. The aggregate can be rock, gravel, sand and the binder is typically a petroleum byproduct that holds the aggregates together. The aggregate and binder are heated to a high temperature and mixed based on the “recipe” and then transported to the job site, loaded into the hopper of the paver and asphalt pavement is laid down, then it is compacted.
Aggregate come in a variety of materials including gravel, sand and stone — and more and more it includes recycled materials. The binder is the most expensive material in the mixture as it is petroleum based, and those costs ebb and flow with market price.
Asphalt pavement is removed when all or a portion needs replacement or utilities require accessing and that’s done in either large chunks or in smaller pieces (called millings). This material can be taken to a landfill but more often it is crushed into gravel size pieces for use in new paving projects. This recyclable material is referred to as Reclaimed Asphalt Pavement (RAP). The additional benefit of using RAP is the binding agents are reactivated when RAP is heated during mixing for the new pavement. This reduces the need for new expensive binders and helps keep costs down.
RAP is not the only material recycled for asphalt pavement. A close cousin to RAP is RAS, Recycled Asphalt Shingles, and the outcome with reactivation of binders is the same with this recycled product. The National Asphalt Pavement Association (NAPA), in partnership with the Federal Highway Administration (FHWA), has been quantifying the use of these technologies for some time through industry surveys. According to recent survey data, the 2015 construction season saw more than 74.2 million tons of RAP and nearly 2 million tons of RAS used in new pavements in the U.S., saving taxpayers more than $2.6 billion, according to NAPA.
This recycling for paving is not limited to asphalt-based products. Other items that are used include ground tire rubber, steel, glass and blast furnace slags. According to NAPA, the reuse of these materials saves about 50 million cubic yards of landfill space each year, thus making asphalt pavement a great contributor to recycling, reuse and sustainability.
The use of these recycled items in asphalt paving saves on energy consumption and new raw material consumption, which works to keep down expenses. Additionally, use of these recycled materials in asphalt pavement keeps them out of our landfills.
Per NAPA, more than 90% of the country’s parking spaces are surfaced with asphalt pavement. Parking lots that have been constructed using recycled materials such as Reclaimed Asphalt Pavement and Reclaimed Asphalt Shingles contribute to a lower cost for the parking lot, lower emissions required from trucking materials in or out, and lower amounts of waste added to landfills. Beyond recycling, asphalt paved parking lots can contribute offer a great space for electric charging stations as well as solar power charging stations. Have you thought about how the asphalt parking lots you have can contribute to the recycling and sustainability goals for your company?
— Christine Knable is vice president of marketing for K.A.I. Total Pavement Management, a Kansas Asphalt, Inc. Company. K.A.I. is a national parking lot maintenance, repair and reconstruction company. K.A.I. uses RAP in its operations, helping customers better achieve their sustainability goals. Kansas Asphalt, Inc. is a woman-owned business.