Crack Reducing Interlayer:
FiberMat® SAMI is a stress absorbing membrane interlayer (SAMI) to seal distressed pavements and retard reflecting cracking of hot mix asphalt (HMA) overlays. A special, trailer-mounted machine applies a sandwiched matrix of polymer modified asphalt emulsion, chopped fiberglass fibers and a second layer of emulsion followed by an application of aggregates by a chip spreader. The tensile strength of the fibers gives outstanding reinforcement to the SAMI. The interconnecting bonding of cured asphalt, fibers and aggregates results in a very tough, very durable interlayer. The process may be used on distressed asphalt, concrete and composite pavements. FiberMat® SAMI layered membranes have been used for years in Australia and Europe, where they have delayed reflective cracking twice as long as road paving fabrics. All States Materials Group is proud to bring this effective, innovative technology to you, our customers.
FiberMat® SAMI Benefits
- Waterproofs and seals cracked, crazed surfaces
- Increased strength and reinforcement of interlayer by fiberglass fibers
- Delays reflective cracking twice as long as fabrics
- Doesn’t wrinkle or tear
- Quick application and traffic return
- Reduces needed thickness of overlays
- Long-lasting protection of pavement structure and new overlay surfaces
The FiberMat® SAMI Application Process
As with all of our paving projects, at All States Materials Group we begin with a design in our laboratory using the project materials. We formulate the polymer asphalt emulsion to break quickly and be compatible with the fibers and project aggregate. After any severe cracks and base and drainage problems are repaired, All States’ trained crew uses an innovative trailer-mounted machine that is equipped with two slot-jet spray bars, a fiber chopping mechanism and compressed air. The first spray bar applies the asphalt emulsion. The machine then uses compressed air to expel the fibers from the chopping mechanism. The fiberglass comes on spools and is cut by the application machine to lengths from 1.2 to 3.5 inches. The operator controls the fiber length and coverage by the blade and rotation speeds. The fibers are immediately covered with emulsion by the second spray bar. The emulsion is typically applied at a shot rate of 0.2 to 0.25 gallons per yd2 for each of the two applications, and the fiberglass at 2 to 4 ounces per yd2. We immediately apply the 3/8" or 1/4" stone seal aggregate with a chip spreader, at typical stone seal rates (just enough aggregate to cover the emulsion). Once the emulsion has set, the surface is rolled and swept, typically within 15 minutes. The membrane may be opened to traffic before the overlay is placed, if necessary. A hot mix asphalt overlay completes the construction.
Where and When to Use FiberMat® SAMI
FiberMat® SAMI can be used on any asphalt or concrete pavement to be overlaid with HMA, including streets, roads, highways and airfields. The high performance system is designed for use on the most demanding highways, where construction delays and reflective cracking are major concerns. There should be no sign of sub-base movements or moisture damage. When warranted, potholes and large cracks should be filled, and any structure or base problems should be repaired. The surface may have aged asphalt with extensive surface cracking, raveling and other surface distresses; or concrete pavements may have severe surface distresses. The surface should be swept of any stones, sand, mud or other loose debris. With the right hot mix overlay, FiberMat® SAMI enables thinner overlay lifts and retards reflective cracking, extending the serviceable life of the overlay. Because it is an emulsion application, FiberMat® SAMI construction should be done on warm, dry days.
A FiberMat® SAMI will extend the life of your overlay. For more information about how All States Materials Group can provide you with innovative treatments for overlay needs, contact us.