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Apr 19, 2013

Bonded Dense Graded Asphalts & UTBWC

Bonded Dense Graded Asphalt/Polymer Modified Asphalt Emulsion

West You can also Discover UTBWC by viewing this Video demonstration

Contracting is a certified, licensed applicator for Bonded Dense Graded Asphalt or Polymer Modified Emulsion Membrane. Within this family of bonded asphalt is also Ultra Thin Bonded Wearing Course (UTBWC). Road Science™ bonded pavement technology – BondTekk®, originated this type of paving method which supports an application process installed by a Spray Paving Machine (commonly called a spray paver). West Contracting travels the Midwest including: Oklahoma, Indiana, Illinois, Arkansas, Iowa, Kansas, Michigan, Tennessee  & Kentucky installing Bonded Dense Graded Asphalts.

The Uniqueness of a Spray Paving Machine (Spray Pavers)

A spray paver is a modified paving machine which is equipped with the emulsion tank and spray bar in the paver in lieu of a traditional paving operation where distributor truck and driver are ahead of the paving operation. By eliminating the distributor truck and driver the paving operation is condensed making the work zone smaller minimizing traffic inconveniences. Another benefit of the “all in one” spray paver is that “tack tracking” is eliminated since there is no chance of traffic or trucks driving through the tack coat before the paving operation covers the tack. Asphalt is installed immediately following the tack coat (emulsion) spray bar (approximately 18” behind).

Closeup of Emulsion Sprayed Directly in front of Asphalt Installation

Why is Bonded Dense Graded Asphalt Better?

Benefits of Bonded Dense Graded Asphalt include the ability to install thinner lifts of asphalt (a huge cost savings) while utilizing emulsion tack and bond strength between the new and old pavement. Strength and life of the new pavement is a direct result of the bond between pavements as well as addressing rutting, cracking, and delamination in the old pavements prior to new pavement installation. The Spray Paving method has proved to be a cost-effective solution to address common pavement ailments while still improving pavements lifetime performance.

Ultra Thin Bonded Wearing Course

Ultrathin Bonded Wearing Course (UTBWC) is a heavy application of a polymer modified emulsion followed immediately by a thin layer of gap graded hot mixed asphalt. The emulsion is applied through a spray bar mounted behind the wheels and immediately ahead of the screed on a conventional HMA paving machine. The hot mix asphalt is installed about 18” behind the Emulsion being applied to the roadway. Ultra Thin Asphalt is usually ½” to ¾” in thickness after compaction.

The process has also been referred to as the NovaChip process, a proprietary system for applying such an ultra thin overlay. The surface produced by this UTBWC is very smooth and open textured, thereby significantly reducing tire/pavement noise and improving skid resistance. The system also provides a waterproof layer and strong bond to existing pavement. UTBWC system is effective in overlaying asphalt and concrete pavements.

Ultra Thin Bonded Wearing Course

Are Bonded Dense Graded Mixes Right for You

Polymer Modified Asphalt Emulsion (PMAE) provides agencies and owners with a broad range of applications to best address their unique needs and preferences for their existing roadways.

Whether the roadway is existing asphalt, concrete, chip seal or another surface treatment the Spray Paving machines have allowed West Contracting to offer Hot Mix Asphalt at a more affordable cost without compromising the strength and overall lifetime of the pavement. Polymer Modified Emulsion Membranes have truly become a significant technological advancement in the Asphalt Industry and West Contracting is proud to be one of the first contractors installing this technology.

You can also Discover UTBWC by viewing this Video demonstration.