Pavement Preservation

James T Andrews on cost effective ways to extend the surface life of a road.

“In 2008, asphalt escalated to well over $800 per ton in some regions, doubling the raw material cost for the most expensive cost component”
-James Andrews

Few of the public may know this, but 94 percent of the paved roads and highways in the US are constructed of asphalt.  Over the last two decades, a new approach to preserving one of our nation’s most vital assets has been evolving since Federal and State agencies have learned that proactive pavement preservation programs are the best means to optimize transportation funding and ensure that tax payer’s dollars are spent in the most cost effective manner. 

Roads can be made to last longer when the right preventive maintenance treatment is used for the conditions to which that the road is exposed.  Historically, the Federal Highway Administration (FHWA) focused on new construction and reconstruction and did not consider maintenance to be a federal responsibility. However, studies by the FHWA examined a number of surface treatments – including microsurfacing, chip seals, slurry seals, and ultra-thin hot mix overlays, as well as not applying maintenance treatments at all – and found that preventive maintenance extends the surface life of a road in a cost effective way and therefore could be eligible for federal aid funding. 

Since pavement preservation maintenance offers the states a way to increase the return on infrastructure investment, the FHWA field offices encourage its use and work closely with state agencies on these technologies. In addition, there is general industry agreement that for every US dollar spent on pavement preservation there is a six-dollar return in extended service life.

An effective pavement preservation system addresses pavements while they are still in good condition, before the onset of serious wear or weather damage.  If agencies changed their maintenance strategy from fixing the worst pavement first, to proactively resurfacing their roads before significant wear on the surface can be detected, their overall efforts could be much more cost effective. Common techniques such as chip seals, microsurfacing, slurry seals, or thin-lift overlays are the technologies used most frequently and by adopting the right maintenance treatment for the right pavement at the right time, the pavement can be restored to almost the original condition. 

The National Center for Pavement Preservation (NCPP) at Michigan State University works with government agencies and industry to advance and improve best practices through research, education, and training.  As part of its activities, the NCPP has recognized that use of polymer modification in surface treatments further extends their cost benefit ratio. It is currently conducting a study for FHWA and it’s Federal Lands Highway Division on polymer modified asphalt emulsions.  This study is expected to help officials decide what types of modifiers and additives to blend with the asphalt binders used in surface treatments.  FHWA also recommends that all pavement preservation applications be polymer modified because of the substantial performance improvement and road life extension.

Pavement preservation also reduces the length of time roads are under construction. Often a resurfacing treatment can be completed in as little as 24 – 48 hours, a significant reduction compared to complete structural reconstruction.  This faster resurfacing time means fewer traffic delays and less traffic congestion, which translates into fewer emissions, less waste and less motorist frustration. 

Rising costs of asphalt and raw materials over the last few years – and increasing demand for limited capital – warrants a more cost effective approach to managing our roadways. In 2008, asphalt escalated to well over $800 per ton in some regions, doubling the raw material cost for the most expensive cost component. Agencies are now finding that budget dollars can go further by using these cost effective strategies to increase overall infrastructure and contribute to a healthier environment.

BASF Corporation is the global leader of styrene butadiene rubber latex polymers (SBR) used in all types of asphalt applications. For decades BASF has been helping road engineers around the world improve performance of their asphalt roads and highways. BASF’s Butonal latex polymers increase the strength and resiliency of asphalt roads under all climate conditions and thereby extend the performance and longevity of the road.

James T Andrews has over 19 years with BASF in various positions including Sales, Marketing, Supply Chain. Currently he is Marketing Manager for BASF Construction Polymers used in the Asphalt market.

For more information about techniques to improve asphalt roads, please visit www.basf.com/asphalt.