Management of two Tasmanian rural road sites affected by black ice formation

The phenomenon of black ice, in which the road surface is covered invisibly by a thin patina of transparent ice, has been known for many years. If not adequately monitored and addressed, such formation of ice on a road surface can result in serious or fatal motor vehicle accidents. This paper analyses two sites on the North-West Coast of Tasmania that are subjected to black ice formation in winter. Site 1 is an asphalt surfaced rural road with a steep gradient located south of the township of Natone. The site has received a maintenance treatment of gritting with crushed aggregate. Site 2 is a steep section of sprayed seal rural road, subjected to heavy vehicle loading from forestry and mining operations. Ultra-high-pressure water cutting (UHPWC) has been used to remove some of the bleed bitumen and return a degree of texture to the road surface. This paper compares the various surface treatments, using the British Pendulum Tester to measure skid resistance (microtextures contribution to friction) and the Sand Patch Test to determine mean texture depth (macrotexture) when subjected to ice. Laboratory asphalt and seal specimens were sourced from a local supplier, with different aggregates sizes and varying polished aggregate friction values (PAFV). This paper reviews the test methods and compared the laboratory and field test results with the investigatory levels of skid resistance and surface textures. Results concluded that dense graded asphalt, due to its low texture depth, performed poorly when subjected to ice. Sprayed seals with coarse macrotexture, such as 10 or 14mm seals, in combination with high PAFV and together with appropriate maintenance, can increase skid resistance when a road surface is frozen. From these results, a double/double preliminary sprayed seal design is recommended for Site 1 & Site 2, and as necessary, apply maintenance through gritting or ultra-high-pressure water cutting.

• Record URL:
  https://arrbknowledge.com
• Authors:
  • Walsh, A
  • Nataatmadja, A
• Conference:
  • Symposium on Pavement Surface Characteristics (SURF), 8th, 2018, Brisbane, Queensland, Australia
• Publication Date: 2018-5

Language

• English

Media Info

• Pagination: 13p
• Monograph Title: Symposium on Pavement Surface Characteristics (SURF), May 2-4, 2018, Brisbane, Queensland

Subject/Index Terms

• TRT Terms: Bitumen; Bituminous pavements; Black ice; Highway grades; Highway maintenance; Ice; Icy roads; Maintenance; Skid resistance; Texture
• Uncontrolled Terms: Pavement technology
• Geographic Terms: Australia; Tasmania, Australia
• ATRI Terms: Asphalt; Gradient; Ice; Icy road; Road maintenance; Skidding resistance
• ITRD Terms: 2806: Gradient; 2775: Rural road; 3031: Skid resistance
• Subject Areas: Maintenance and Preservation; I23: Properties of Road Surfaces; I62: Winter Maintenance;

Filing Info

• Accession Number: 01678446
• Record Type: Publication
• Source Agency: ARRB
• Files: ITRD, ATRI
• Created Date: Aug 23 2018 2:37PM