Talking Asphalt: Emphasizing preservation – January 2011

Talking AsphaltIt seems to me that the time for focusing on the construction of new highways has largely passed. Yes, there will be some new projects—lane additions, bypasses, realignments and even a few completely new routes. But, in the U.S., our primary focus has, or should be, shifted to maintaining the highways we have in place. That means pavement preservation, which can be described as a strategy for managing pavement conditions to maximize the pavement’s life at minimal cost.

For some of us, pavement preservation is a big challenge. I come from a hot mix background, and I see the issue as simply adding new tools to what we’ve always used. To make this change, we need to overcome a few mental hurdles and then gear up to do the work.

Before making wholesale changes in our approach, we need to have a well thought out plan for addressing our pavements. Using the same old approach may not be the best way. There may be other, or new, materials or techniques that will work better and save time and/or money. It may be time to look at some other options. But before a shift is made, management will have to make a commitment and there will need to be communication between owners/agencies and contractors.

Agency management will have to guard against the practice of addressing only the worst pavements. With funding shortages, it’s easy to tie up all the funds fixing the obvious needs. But some of the funds need to go towards “keeping good roads good.”

Asphalt contractors may have to make a few changes. My experience has been that asphalt contractors are, first and foremost, business people. They want to supply a service for a reasonable return and will adjust to changes in their business. Contractors need to understand what is expected and to have sufficient volume of work to invest in new people or equipment. Like “build it and they will come,” if enough work is there, it will get done.

Another hurdle to overcome is that we are more comfortable applying pavement preservation techniques to low-volume roadways than to high-traffic roads. And that makes sense. If we lack experience with a given preservation strategy, it probably is best to gain some experience where the risk is less. Don’t do your first micro-surfacing job on your most visible road. Get some experience on less critical sites then move up to higher type facilities.

We are already familiar with some of the pavement preservation tools, such as thin HMA or WMA overlays and crack sealing. These approaches can be widely used for preservation. Other techniques, such as slurry seals and micro-surfacing, may be less familiar to some agencies and contractors. However, these techniques have been used extensively and a great deal of information and expertise is available for those interested in trying new techniques. The International Slurry Surfacing Association (ISSA; is a good place to start.

It may be time to start looking at some of these treatments.