ASPHALT SURFACE TREATMENT
First introduced to the asphalt market over forty years ago, the use of lightweight aggregate in the United States exceeds 3,000 miles of asphalt pavement annually. Lightweight aggregate asphalt paving has been used throughout the country because it offers many advantages over asphalt made with ordinary aggregates including but not limited to competitive total installation costs.
When bonded to asphalt, structural lightweight aggregate chip seal creates a significantly improved asphalt bituminous surface treatment that is safer, more economical and longer lasting than conventional aggregates. Wet or dry, road surfaces of lightweight chip seal provide superior skid resistance that is maintained throughout the surface life. Lightweight aggregate does not polish as it wears. Because it is light in weight there are trucking and handling cost advantages to the contractor.
SELECTED CASE STUDIES
LIGHTWEIGHT AGGREGATE USED AS ICE CHAT IMPROVES SAFETY FROM WINTER WEATHER
The surprisingly extreme winter conditions in North Texas produced uncommon amounts of accumulated precipitation – ice and snow – in the first two weeks of February 2011. Although the inclement weather curtailed sales to most of our customers, the weather did provide the opportunity to address needs in the maintenance marketplace.
ARCOSA’s Streetman Expanded Shale Plant successfully delivered over 12,000 cubic yards (CYDS) of Grade 5 Modified “Ice Chat” to several TXDOT Districts, Local County and City Maintenance Units, as well as several private institutions.
Interestingly, a finer blend of the material was also used on some of the walkways around the Dallas Cowboy Stadium during Super Bowl XLV.
CHIPSEAL DELIVERS ECONOMY, LONGER LASTING ROADS IN NEBRASKA PROJECT
When the Nebraska Department of Roads needed a way to economically extend the life of 6 ½ miles of pavement on State Highway 61, just south of Ogallala, they turned to a chipseal solution utilizing expanded shale lightweight aggregate from Arcosa Lightweight, for both its excellent performance and its economical cost.
Chipseals -- used to extend the life of asphalt pavements -- are applied by evenly distributing a thin base of hot emulsion onto an existing pavement and then embedding well-graded aggregate. The aggregate is evenly distributed over the seal spray, then rolled into a smooth pavement surface.
In the case of the of the Highway 61 project, the Nebraska Department of Roads used a new technique -- a heavier application of emulsion, and a “fogging” of the road surface with another round of emulsion after the initial application of emulsion and aggregate had cured for 10 days. “We shot the emulsion at a considerably heavier rate than we normally do with chipseals, and then we applied the fog coating of emulsion,” Radke said.