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Recycling Asphalt Rescues Roads

Solving the Maintenance Riddle

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Hesham Ali
ALI

It is no secret that all levels of government are facing unprecedented budget deficits. While state and municipal revenues are dropping, infrastructure needs are growing and the question of sustainability is taking center stage. Can we afford to keep those infrastructure assets and all four million miles of paved roads in the U.S.? I work with asphalt every day, and I can tell you from my long experience that there are some good answers.

Recycling Asphalt Rescues Roads
Photo: Donna Short
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In 2006, the 50th anniversary of the Interstate Highway System highlighted the contrast between the condition of the roads in recent years and their condition when the system was inaugurated. Built in the 1960s, the system was an undertaking that successfully constructed the highway backbone of the U.S. Among other factors, it propelled this country to its position as a world leader.

With 42,795 miles of primary highway network, the system was “capable of taking us to every corner of the United States” on highways that “are the safest in the country by a factor of two,” according to Dan McNichol’s “The Roads That Built America” (2003).

The robust economy of the 1990s and the early 2000s provided no incentive for efficiency and cost savings in the maintenance of our road network. Without any economic pressure, highway agencies felt comfortable with their customary ways and lacked motivation to think outside the box and demand more for less. In short, the good times brought with them a less-than-disciplined and less-than-efficient approach to asset management when it came to our roads.

That mind-set is changing. Financial hurdles have underscored the importance of treating roads as assets to be efficiently managed.

Fifty-plus years after the system’s creation, we are confronted with a road maintenance problem as big as the system itself. The status quo is not sustainable, and state departments of transportation need cost-effective solutions or face going back to the transportation Stone Age and possible extinction.

There are answers. In Michigan, at least 38 counties have converted some asphalt roads to gravel. Counties in Alabama and Pennsylvania have begun downgrading asphalt roads to cheaper chip-seal roads. Some counties in Ohio are simply letting roads erode to gravel.

New Pavement Rehab Paradigm

Recycling asphalt may be a better option for some roads.

Nevada’s Dept. of Transportation has saved $700 million so far in pavement recycling projects. Studies have shown for many years that pavement recycling is cost-effective, saving up to 50% of rehab cost.

Florida’s Dept. of Transportation compared hot-in-place pavement recycling to conventional milling and resurfacing on its state Road 471. The comparison looked at the cost of resurfacing versus recycling and assumed 18 years of service life for milling and resurfacing and 14 years of life for recycling. The annualized cost of resurfacing was 61¢ per sq yd per year in 2002 dollars, while the annualized cost of recycling was 40¢ per sq yd per year in 2002 dollars, or a 35% savings. If FDOT spends $300 million on pavement resurfacing annually, the savings can reach $100 million a year. And that’s not counting economies of scale.

If pavement recycling becomes mainstream, more contractors will enter the field and the price will fall, perhaps saving, for instance, Floridians another $150 million a year. Once barriers are lifted and technical challenges met, the rewards will be great.

An example of what this can mean is provided by the recent $10-million, hot-in-place asphalt recycling project involving 14 miles of State Road 700 near Canal Point, Fla. My company had a key subcontract on that project and the benefits of asphalt recycling included $700,000 in savings, eliminating 24,000 tons of asphalt millings and the need to mine 24,000 tons of new materials. Florida also saved the cost of 300,000 gallons of asphalt cement, which would have had to be trucked to and from the work zone. And all this was accomplished while meeting mix-gradation and surface requirements.

Highway agencies, developers and homeowner associations would be wise to add recycling to their pavement-rehab tool kit.

 

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