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22 nd Conference Roads and Works - 2014 Asphalt Trial – Outcomes so far. Rod Ellis Board Member IPWEA SA. Binder Filler Aggregate. What is Asphalt?. Light Vehicles No heavy turning Less 5E10^5 ESA. Low Volume Roads. Lower air voids needed to slow oxidation. Why the Trial ?.
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22nd Conference Roads and Works - 2014Asphalt Trial – Outcomes so far Rod Ellis Board Member IPWEA SA
BinderFillerAggregate What is Asphalt?
Light VehiclesNo heavy turningLess 5E10^5 ESA Low Volume Roads
Lower air voids needed to slow oxidation Why the Trial ? Higher Binder needed to resist water penetration
Because we need to slow aging process
Linden et al (1989) “Asphalt pavement life is reduced by 10% for each % increase in voids above 7%” • Oliver 1992 “Ageing of binder greatly reduces for mixes that are compacted to 6% air voids and below” APRG technical noted light duty non structural asphalt surfaces and overlays (July 1997) • Aims: Low air voids (density) • High bitumen content (impermeability)
Target 4-6% field air voids Goal of trial
Local Government Research and Development Scheme 2012 • Led by The City of Salisbury with additional funding by the following Councils: • City of Salisbury • City of Burnside • City of Playford • City of Port Adelaide Enfield • West Torrens City Council • Adelaide Hills Council • City of Adelaide • City of Unley • City of Marion • Light Regional Council • IPWEA SA
Collaborative Contribution of Expertise
A: C320 B: C320 WMA C: C170 RAP D: C170 RAP WMA
Fine AC mix DPTI – Part 227 and 228 – Fine AC mix http://www.dpti.sa.gov.au/contractor_documents/specifications_-_division_2_roadworks
More fillerMore binderMore workableMore surveillance What did we learn? Low voids High voids
Field Voids range 3-6% Field Voids (Average 6.5-7.5) - range 5.5-10% Target Current Practice
2014 LGA R&D Application15 sites - Fine AC 10WMA and RAPLaboratory Testing Durability Next step?
Road Surface Management Field and Accounting Treatment
Accounting Consideration • What defines the surface asset • Top surface • Multilayered surface (componentised?) • Surface Type • Hotmix, Spray Seal, Slurry • End of Life • Resurface no preparation • Resurface with patching • Resurface with pavements rejuvenation
Intergenerational Consideration • Examples • Hotmix every 25 years( high voids) • Hotmix every 40 years (low voids) • Hotmix then after 40year spray seal • Spray seal every 20 year • Factors • Double and single • Edge profile cost or full width profile • Hotmix Field voids linked to life
State Built up Low Volume Sealed network – 7640km (27 Councils) Large Centre‘s
Rejuvenation ( management option for high void asphalt ?)
Possible 100yr cost profile with Rejuvenation( typical Street)
The Size of Opportunity • Councils with Large Urban Road Networks • 7640km, 27 Councils • Adopt low void hotmix (Fine AC) • Adopt a WOL strategy including all treatment options to extend AC life • Annual saving over $10Million to the state • Councils with Small and Remote Urban Roads • 2230km, 41 Council • Spray seal treatment selection critical
The Size of Opportunity • Rural Road Network (outside Urban Centres) • 7400km, 68 Councils • Proactive Maintenance • Edge, Shoulder and drainage • Early intervention for resealing Note – many roads grant funded for construction but renewals are funded by council.
Products • Polymer • Micro surfacing • Rejuvenation • AC10M, Fine AC10 • C320,C170 • WMA • RAP
22nd ConferenceRoads and Works - 2014To Spray or Not to Spray Rod Ellis, Board Member IPWEA SA Peter Levett - City of Salisbury Kelly Manning - AAPA