2. Course Objectives
To provide participants with an overview of asphalt
surfacing 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.
6.
7.
8. 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, approx
160oC, and placed as a hot material at >90oC
9. 1. Basic Principles of Asphalt
Performance Requirements of Asphalt
Resistance to permanent deformation (ie rutting)
Resistance to fatigue
Durable
Workable (for placement)
Good Skid resistance.
Specialist mixes that have added performance
properties such as low noise, low spray generation, or
increased resistance to cracking or rutting
10. 1. Basic Principles of Asphalt - Binder
Binder is the ‘glue’ that holds all of the asphalt mix
components together.
Can be Class 170, 320, 600 or multigrade bitumen.
Class 320 most commonly used
Can include polymer modified binders to enhance the
performance properties of the bitumen and is commonly
used in high performance mixes such as SMA and OGA
11. 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 rock
with minimal unsound stone
VicRoads Specification 407 and 831 cover the various
requirements for asphalt aggregates
12. 1. Basic Principles of Asphalt - Filler
Filler materials are particles that are smaller than
0.075mm.
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 rely
on the mix design and available materials
13. 2. Use and Types of Asphalt
Use of Asphalt
Structural part of the pavement – deep lift asphalt,
typically >150mm depth
Wearing (top) surface of the pavement – typically
<40mm
Patching of failed pavement areas
Regulation to improve ride quality and remove
depressions
14. 2. Use and Types of Asphalt
Types of Asphalt
Hot asphalt, cold asphalt, warm mix, warmix and
premix
Asphalt for wearing surfaces
Asphalt for structural layers
Various sizes of asphalt mix -7mm, 10mm, 14mm,
20mm, 28mm
Binders
– Bitumen, Emulsion, Polymer Modified Binder
15. 2. Use and Types of Asphalt
Types of Asphalt
Different types of asphalt wearing surfaces
– DGA Dense Graded Asphalt
– SMA Stone Mastic Asphalt
– OGA Open Graded Asphalt
– UTA Ultra Thin Asphalt
(UTA, Novachip)
– RGG Regulation Gap Graded Asphalt
17. 2. Use and Types of Asphalt
Dense Graded Asphalt
– Most common asphalt type
– Dense, continuously graded aggregates and filler
– Used for structural layers in asphalt pavements
(Types SI, SS and SF)
– Used for Wearing courses on both granular and
asphalt pavements (Types H, V and HP)
19. 2. Use and Types of Asphalt
Stone Mastic Asphalt
– Uses gap graded aggregates with a larger proportion
of coarse aggregates that interlocks give a strong
interlocked matrix
– Includes fibres and a Polymer modified binder
– Used as a wearing course only
– Provides a strong and robust surfacing that has
increased resistance to rutting and cracking.
21. 2. Use and Types of Asphalt
Open Graded Asphalt
– Wearing course only
– Uses predominantly coarse aggregates and small
amounts of fine material
– Provides a mix with a high volume of air voids
– Used as a textured, porous surfacing that assists
with noise and spray reduction
– Used almost exclusively on Freeways
– Expected life up to about 12 years
23. 2. Use and Types of Asphalt
Ultra Thin Asphalt
– Used as a wearing course only
– Similar properties to OGA but to a lesser extent
– Developed to be placed in thin layers (typically
25mm)
– Used where an asphalt surface is desirable but levels
are an issue, (Kerb and chanel or an as alternative
to sprayed seal surfacing
– Expected life 10-12 years
25. 2. Use and Types of Asphalt
Regulation Gap Graded Asphalt
Primarily used as a regulation layer to even out surface
roughness prior resurfacing
Increased binder content and gap graded aggregate
Has greater workability and can be placed in very thin
layers and ramped or feathered out to zero depth
27. 2. Use and Types of Asphalt
Types of Asphalt
Different types of DGA asphalt for structural layers
– Type SI Structural Intermediate
• Multipurpose for heavy duty pavements, or base
course for medium duty pavements
• Type SP Structural PMB (intermediate layer)
• High resistance to deformation at very heavily
trafficked intersections
– Type SS Structural Intermediate for Stiffness
• Stiffness layer for large scale heavy duty asphalt
pavement
– Type SF Structural Fatigue
• Fatigue resistant base course for heavy duty
pavements (must be covered by 100mm of other
asphalt)
28. 3. Asphalt Mix Design
Mix design undertaken by Asphalt production company.
Selection of “Ingredients”
– Aggregate type
– Filler material
– Aggregate grading
– Binder type & Content
30. 3. Asphalt Mix Design
VicRoads Registration System
Contractual requirement of all VicRoads Contracts that
mix designs used on VicRoads works must be
Registered.
Mixes can be registered as:
– General Mix
• Complies with VicRoads Standard Specifications.
– Non Standard Mix
• Proprietary and other mixes that do not comply in
all respects with the requirements of this Code of
Practice but where successful field trials have
been undertaken for a period of at least three
years and the mix performance continues to be
closely monitored.
31. 3. Asphalt Mix Design
VicRoads Registration System
– Experimental Mix –
• A mix that does not comply with the requirements
of this Code of Practice and for which there is
little or no history of successful performance and
requires more trials to be undertaken and
monitored before it is registered as a Non
Standard or Conditional mix.
– Conditional Mix –
• Mixes which do not comply in all respects with the
requirements of Standard Specifications but
which are considered appropriate for use subject
to conditions attached to the registration.
32. 3. Asphalt Mix Design
VicRoads Registration System
– Superseded Mix
• Superseded by another registered mix but details
are retained for record purposes.
– Withdrawn Mix
• Withdrawn from use because of unsatisfactory
field performance but details are retained for
record purposes.
33. 3. Asphalt Mix Design
VicRoads Registration System
All mix designs reviewed and recorded by Technical
Consulting and stored in a database.
Registrations last for two years and must be renewed
New mix designs required if any of the components
change
Mixes registered as General should only be used unless
advice is sought from Technical Consulting.
Database contains commercially sensitive information
and should not be distributed.
49. 5. Treatment Selection
Wearing Courses
DGA Type L very lightly trafficked pavements,
<500AADT
DGA Type N light to medium duty,
<3000AADT
DGA Type H heavy duty,
>3000AADT
DGA Type HP heavy duty, cracked area
>3000AADT
DGA Type V signalised intersections, roundabouts,
>5000AADT
50. 5. Treatment Selection
Wearing Courses
SMA improved crack resistance, high texture, rut
resistance
SMAN for midblock, SMAH for intersections
OGA reduced water spray and noise, high texture
high speed facilities, multiple lanes
UTA increased texture, flexible, shorter service
life
66. 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 and
Bridgeworks
Editor's Notes
Asphalt is placed by paver with depth controlled by paver crew Picture shows small paver New asphalt in foreground
Truck, paver, roller all working together End Peter
See water been sprayed to prevent pick up
The aggregate component is made up of both fine and coarse aggregates. Coarse aggregates are defines at this that are large enough to be retained on a 4.75mm sieve. Fine aggregates are those that pass this sieve but are larger than 0.075mm Less than the 0.075mm sieve is deemed to be ‘filler’ material Aggregates need to from a rock source that produces hard and durable stone and needs to be clean and washed before being used in asphalt mixes. VicRoads Standard Specifications 407 and 831 specify the various requirements for rock such as grading requirements for coarse, fine and filler materials, rock types, and other various properties.
Filler materials are any materials that are smaller than 0.075mm. These can include Natural or manufactured sand Crusher dusts – a by product of crushing rock into aggregates Hydrated lime Slag or ground granulated blast furnace slag which is a by product of steel manufacture Fly ash – a by product from the combustion of coal Ground limestone Cement Kiln dust – a by product of cement manufacture where the dust us collected from the flue gasses during the manufacture process. The actual filler material will vary from mix to mix and be dependant on the mix design and available materials.
Use of Asphalt Asphalt may be used as a structural part of the pavement – deep lift asphalt, typically >150mm depth The depth and type of asphalt are designed into the pavement to provide strength, stiffness, and resistance to deformation – rutting Asphalt may be used as only the wearing (top) surface of the pavement – typically <40mm VicRoads use includes asphalt patching to 150mm depth Asphalt patching is quick and long term – less traffic disruption
Hot asphalt normal VicRoads resurfacing and pavement works cold asphalt and warmix patching and regulation material for maintenance patrols premix patching and pothole repair material for maintenance patrols Different types of asphalt wearing surfaces; DGA standard wearing course – most used asphalt SMA increased texture and rut resistance for sig ints and high speed areas (>80kph) OGA increased texture and free-draining to reduce water spray from congested, high speed sites, reduced traffic noise Eastern Fwy and Western Ring Rd UTA UTOGA, PLCS, thin asphalt for increased texture, low noise, for flexible sites, midblock, not sig int RGG regulation works, asphalt used to correct shape loss of pavement, especially in small areas Sizes PMB Samples of different asphalt types Expensive typically $12-20/m2 when bought in large volumes costs vary across the State according to usage, quantity and distance to site
Hot asphalt normal VicRoads resurfacing and pavement works cold asphalt and warmix patching and regulation material for maintenance patrols premix patching and pothole repair material for maintenance patrols Different types of asphalt wearing surfaces; DGA standard wearing course – most used asphalt SMA increased texture and rut resistance for sig ints and high speed areas (>80kph) OGA increased texture and free-draining to reduce water spray from congested, high speed sites, reduced traffic noise Eastern Fwy and Western Ring Rd UTA UTOGA, PLCS, thin asphalt for increased texture, low noise, for flexible sites, midblock, not sig int RGG regulation works, asphalt used to correct shape loss of pavement, especially in small areas Sizes PMB Samples of different asphalt types Expensive typically $12-20/m2 when bought in large volumes costs vary across the State according to usage, quantity and distance to site
Added by CS
Dense graded asphalt as the name suggests is a dense asphalt made up of Binder, fine and coarse well graded aggregates, and filler materials
Hot asphalt normal VicRoads resurfacing and pavement works cold asphalt and warmix patching and regulation material for maintenance patrols premix patching and pothole repair material for maintenance patrols Different types of asphalt wearing surfaces; DGA standard wearing course – most used asphalt SMA increased texture and rut resistance for sig ints and high speed areas (>80kph) OGA increased texture and free-draining to reduce water spray from congested, high speed sites, reduced traffic noise Eastern Fwy and Western Ring Rd UTA UTOGA, PLCS, thin asphalt for increased texture, low noise, for flexible sites, midblock, not sig int RGG regulation works, asphalt used to correct shape loss of pavement, especially in small areas Sizes PMB Samples of different asphalt types Expensive typically $12-20/m2 when bought in large volumes costs vary across the State according to usage, quantity and distance to site
Discuss Slide Aggregate includes coarse aggregate, fine aggregate and fillers.
Mix designs are undertaken by the Asphalt production company The process of Asphalt Mix design involves the choice of aggregate type, filler, combined aggregate grading, binder type and determination of binder content to optimize the engineering properties of the asphalt mix.
Once the ‘Ingredients” are determined Small samples of the proposed mix are prepared in a lab The volumetric properties of the mix are determined followed by mechanical testing of the mix to determine its general performance characteristics. Once it has been determined that the ‘recipe’ will produce a satisfactory mix, based on the volumetric properties and mechanical testing it can be Registered and is ready for production. There are specific test methods and Australian standards that cover the methods and procedures for the design and testing of asphalt mixes.
Database is important because this is how VicRoads control the basics of asphalt quality
Auditing of asphalt production plant specialised auditing by GeoPave and VicRoads staff can come too! Includes: General Requirements : Plant capacity. Compliance with safety, fire hazard, environmental and land use requirements. Raw material storage quantities adequate for continuity of production. Sampling of raw materials. Aggregate storage – separation, identification and prevention of contamination. Stockpiling and handling of RAP Filler storage. Binder storage, including temperature control of binder tanks. Temperature of binder supply. Binder discharge sampling. Binder heating temperature. Aggregate feeders. Adjustment of feeders. Calibration of feeders. Purchaser access to plant during operation. Batch Processing : Aggregate dryer, including moisture content of dried coarse and fine aggregate. Temperature of mixed material. Temperature of aggregate discharge from dryer. Hot aggregate screening: no of bins operation of bins effective overflow device low level indicator sampling device Weighing of materials. Automatic batching - visual mass indicators. Plant access to standard test weights for calibration. Binder discharge into mixer. Mixing time. Discharge temperature of mix. Discharge method and minimisation of segregation. Continuous Processing: Feeding of cold aggregate – warning of lack of aggregate flow. Drying and heating. Mixing: automatic burner controls mixing temperature moisture control Prior to Start Up : Check sufficient quantities of quality raw materials ready for manufacture without contamination of stockpiles or binder type. Check bins filled; feeders clear and set; cold feed conveyors clear, free and tracking. Check dryer working; hot elevator free; buckets intact; screens sound and running smoothly; pugmill / mixer operational. Check binder temperature. Start Up/During Production : Check feeders, fans, conveyors, drum, readouts, hoppers, storage, weigh bins and burner operation. Check feed rate matches production rate - balance feed rate to moisture content and temperature of mix. Check temperature variations of binder, hot aggregate and mixed asphalt. Check clean omission from stack. Check no contamination of mix types particularly during change over of mixes. Shut Down : Check further production needs prior to shut down. Check uniform run down of materials. Check no material in screen house overflow; oversize material in reject bin; spillage of cold feed or asphalt. No filter bag damage in bag house and conveyor, dryer, hot elevator, screens, hot bins, weigh hopper, pugmill clear of all material. Check stock levels remaining. Check any plant components that malfunction during production.
Checking the mixed asphalt in the lab Quartering the sample after sampling, this ensures a uniform well distributed sample is analysed. Accreditation Laboratory testing accreditation status displayed and proficiency testing is current. Control of documents and data . Copies of test methods available and current. Recording of samples up to date and complete. Laboratory environment Personal protection equipment used. Relevant MSDS available. Compliance with MSDS or laboratory safety rules. Laboratory Staff Training records show that technicians have been assessed as competent and proficient. Inspection and testing Correct test procedures followed and accurately recorded. Non-conformances System followed for recording and corrective action for all non-conformances including use of Business Improvement Reports. Calibrations Check that calibration files are maintained and current for all relevant laboratory test equipment.
COP 500.22 Appendix D and 500.01/ section 408 Table 407.021
COP 500.22 Appendix D and 500.01/ section 408 Table 407.021
Blackburn Road, south of Highbury Rd, medium traffic, midblock, 60kph
DVH and Wellington, 80kph, heavy traffic
WPH and Thompsons Rd, heavy traffic, 80kph
Residential roundabout
FGR 80kph heavy traffic
Eastern Fwy at Springvale Rd
DVH SBC 70kph
WPH OBC 100kph
WPH IBC 100kph
This is a list of information tips, hints and information that will lead to an improvement to your road surfaces. Each of these and other are continually being updated and added to.
