Frequently Asked Questions

Why should we consider using ACE XP™ Polymer Fiber?

ACE XP™ is made of aramid which has been proven to increase the strength, crack resistance, rut resistance, fatigue life, toughness and service life of any asphalt concrete mixture.

How does ACE XP™ increase performance?

Testing on ACE XP™ has produced results showing 140% increase in crack resistance and 60% increase in rut resistance.  Aramid has also been the subject of numerous U.S. and international asphalt performance studies over the past 15 years. Fiber additives for asphalt concrete have a history dating back more than 40 years, but it has been the recent advancements in materials and the way pavement researchers test and quantify performance that has confirmed the predictability and reliability of aramid for asphalt concrete pavements. The combination of historical and recent research, testing, and case studies demonstrate the active material in ACE XP™ Polymer Fiber significantly enhances asphalt concrete pavement performance.

What does ACE XP™ do in asphalt?

Simply put traditional asphalt concrete is “rocks and glue”. While the aggregate (rock) in asphalt concrete provides compressive strength and wearing resistance, the asphalt – while a practical and smooth pavement, has properties vulnerable to temperature changes.  When cold, it has a tendency to become brittle and crack, and when warm/hot it has a tendency to soften and flow, which leads to rutting.  Since aramid is a fibrous tense solid, its properties remain consistent whether it’s cold or hot. When the asphalt is cold, aramid fiber will help reduce the cracking effect of asphalt concrete by adding significant tensile strength. When asphalt is warm/hot aramid fibers resist rutting because the fibers are imbedded and rooted in the asphalt to resist flow. ACE XP™ Polymer Fiber significantly increases the tensile and binding strength of asphalt concrete.

How do you use or design asphalt mixes with ACE XP?™

We have two different approaches to asphalt concrete pavement designs with ACE XP™.

  1. Standard practice – This method is simply using aramids fiber’s performance enhancements and applying them your current asphalt concrete pavement design. If an agency wants to have longer lasting asphalt pavement, it can simply add ACE XP™ to its mix.  ACE XP™ can specifically be used to add extra reinforcement to busy intersections, bus lanes, loading areas and challenging road sections that have a history of cracking/rutting or failing prematurely.

When a street maintenance department uses ACE XP™, you can reduce your pavement sections from a 3-inch A.C. overlay to a 2-inch A.C overlay without sacrificing performance. This will save you approximately 33% cost savings allowing the redeployment of resources into 33% more overlays in maintenance projects.

The reduction in thickness more than offsets the cost of ACE XP™ while enjoying increased performance and life.

  1. Modified Structural Numbers/Layer Coefficients– Depending upon which pavement design method is used, pavement engineers can design A.C. pavement sections with aramid fiber by modifying their structural numbers or layer coefficients in their design programs. For instance, if a pavement designer is using AASHTO, they can use an enhanced layer coefficient in their design program for the asphalt layout because the fiber mixed asphalt has significantly higher performance characteristics. The pavement designer can then decide how to use the enhanced asphalt performance for thinner asphalt, aggregate, or other layers to save costs, increase life, or a combination of both.

Is ACE XP™ difficult for asphalt plants to mix?

No. For batch plants the proper amount of ACE XP™ Polymer Fibers is put into the weigh hopper and mixed as usual. For drum plants, ACE XP™ Polymer Fibers are manually or mechanically fed onto the RAP belt or blown into the RAP collar at the rate the drum is mixing A.C. ACE XP™ can be fed with different kinds of mechanical feeders that are easy to hook-up without plant modifications. For an additional cost, Surface Tech can also provide third party mixing services performed by licensed and trained engineers to ensure uniform distribution. Pre and post mixing reports are done at the plant or in the field by a licensed engineer to ensure that the proper amount of ACE XP™ was added to the amount of A.C. ACE XP™ Polymer Fibers are pre-treated so that the fiber filament clips drop into the asphalt mixture and disperse uniformly with the mixing of a batch chamber or spinning of the drum chamber. The individual fibers are also visible upon inspection of fresh asphalt mix.

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