1.Asphalt PrinciplesFebruary 2012

2. Course Objectives To provide participants with an overview of asphaltsurfacing types and their application 3. Learning Objectives Participants will develop an understanding of: Asphalt surfacing design and selection Asphalt principles and practice 4. Course Outline The session will cover: Basic Principles of Asphalt Use and Types of Asphalt Asphalt Mix Design Asphalt Production Treatment Selection 5. Basic Principles of Asphalt Engineered material comprising of Bitumen, aggregate,filler and air voids. Has engineering properties that can be used for design. Asphalt is produced according to asphalt mix designs(recipes) based on raw materials Asphalt is typically produced as a hot material, approx160oC, and placed as a hot material at >90oC 6. 1. Basic Principles of AsphaltPerformance Requirements of Asphalt Resistance to permanent deformation (ie rutting) Resistance to fatigue Durable Workable (for placement) Good Skid resistance. Specialist mixes that have added performanceproperties such as low noise, low spray generation, orincreased resistance to cracking or rutting 7. 1. Basic Principles of Asphalt - Binder Binder is the glue that holds all of the asphalt mixcomponents together. Can be Class 170, 320, 600 or multigrade bitumen. Class 320 most commonly used Can include polymer modified binders to enhance theperformance properties of the bitumen and is commonlyused in high performance mixes such as SMA and OGA 8. 1. Basic Principles of Asphalt - Aggregate Coarse aggregate ( larger than 4.75mm) Fine aggregate (between 4.75mm and 0.075mm) Less than 0.075mm material is called filler Aggregates need to be hard, clean and durable rockwith minimal unsound stone VicRoads Specification 407 and 831 cover the variousrequirements for asphalt aggregates 9. 1. Basic Principles of Asphalt - Filler Filler materials are particles that are smaller than0.075mm. Can include natural or manufactured sand crushed material (crusher dust) hydrated Lime, Slag, Fly ash, ground limestone, cement, kiln dust The actual filler materials vary between mixes and relyon the mix design and available materials 10. 2. Use and Types of AsphaltUse of Asphalt Structural part of the pavement deep lift asphalt,typically >150mm depth Wearing (top) surface of the pavement typically5000AADT 44. 5. Treatment Selection Wearing Courses SMAimproved crack resistance, high texture, rut resistance SMAN for midblock, SMAH for intersections OGAreduced water spray and noise, high texture high speed facilities, multiple lanes UTAincreased texture, flexible, shorter servicelife 45. Blackburn Road,midblock, 60kph,medium traffic, low HV 46. Stud Road, intersection, 80kph,heavy traffic, 10% HV 47. Westernport Highway, roundabout, 80kph,heavy traffic, 15% HV 48. Holland Road,roundabout, 50kph, low traffic, low HV 49. FGR, midblock,80kph, heavy traffic, 15% HV 50. Sesame St, midblock,60kph, low traffic, low HV 51. Eastern Fwy, midblock, 100kph,heavy traffic, 10% HV 52. DVH, midblock, 70kph,medium traffic, high HV 53. Westernport Hwy Road, midblock,100kph, medium traffic, high HV 54. Westernport Hwy Road, midblock,100kph, medium traffic, high HV 55. References Austroads/AAPA Work Tips (www.aapa.asn.au) APRG Technical Notes VicRoads Technical Notes Austroads Pavement Technology Series 4B: Asphalt Australian Standards VicRoads, Standard Specification for Roadworks andBridgeworks