Development of long life structural asphalt

Transcription

1 Build something great Development of long life structural asphalt Trevor Distin Sustainability opportunities for the asphalt industry Reusing RAP Preservation of raw materials bitumen & aggregates However limited amount available Recycling waste Recycled crushed glass, crumb rubber from tyres, steel slag, ink toner Substitutes for virgin materials Lowering mix temperatures Reduces energy consumption Reduces GHG emissions Asphalt surfacings should last longer Increase structural strength Longer life Requires less maintenance Reduced user delays Reduced demand for raw material Reduced GHG emissions per t/km of freight Less temperature susceptible 2 1

2 Long lasting structural asphalt Enrobés à Module Elevé (EME) Development of EME How is EME different from HMA Benefits of EME Transfer of EME to Australia 3 Development of EME? Developed in France in the 1980 s for A380 airbus Use in specs for roads in 1990 s Introduced into European highway specs in 2005 Has been used in projects in Reunion, Mauritius & South Africa since 2007 First used in Brisbane in February

3 Evolution of EME in France Binder pen Modulus Grade [1/10 mm] Modulus [100 MPa] Grade Modulus Binder content Binder content [ppc] Binder Content Pavement thickness Fatigue What makes EME different from HMA? Flexibility EME 20 C 500k cycles 100k cycles DG20 MG DG MPa BTB 9000 MPa 25 C Stiffness 3

4 Principles behind EME Property Increased fatigue - Increasing binder content in the mix Increased modulus - By using a very stiff binder Improved rut resistance - Achieved through stiff binder Improved moisture sensitivity - Increased binder content Improved workability - Increased binder content Test DG20 EME2 20 C, cycles to failure 25 C 40, , MPa 10.8 MPa Rut 60 C 2.9 mm 1.2 mm Tensile Strength Ratio & value 99% 758 kpa 101% 1280 kpa Performance based mix design process Workability Moisture resistance Level 1 Rut resistance Level 2 Binder content Level 3 Level 4 Modulus Fatigue resistance Bitumen properties 4

5 Benefits of EME performance 1. Reduction in layer thickness 30% reduction in equivalent structural layer thickness Benefits of EME performance 2. For the same layer thickness EME will provide a pavement with a longer structural design life require less structural maintenance allow an increase axle load limits - Australia 9t vs France 13t reduction in cost of freight per tonne render our goods more competitive for export 5

6 Benefits of EME performance 3. Reduction in construction costs for new or distressed pavements: No need to raise kerbs & channels or bridge decks Remove need for waterproofing seals in layers Less excavation for new pavements Reduced time required to pave thinner pavement layers Benefits of EME performance 4. Environmental benefits Reduced consumption of non-renewable materials - Bitumen, aggregates - Energy in manufacture & transport Less structural maintenance & traffic disruption Can carry heavier loads reduces GHG emissions per tonne/km of freight Pavements less susceptible to climate change 6

7 Transfer of EME to Australia 1. Austroads commissioned ARRB in 2012 to undertake an explorative study 2. Develop locally available EME binder - SAMI conducted performance tests on imported EME from France using Austroads tests - Test mix using local Boral aggregates and experimental binder - Completed June Conduct EME mix design using French test methods on local materials - Shipped materials to Colas central lab in France in March Whinstanes mix design completed October 2013 & West Burleigh in February 2014 Transfer of EME to Australia 4. Manufacture and pave EME using local materials Involvement of all stakeholders Access road to Boral s asphalt plant Constructed pavement in Feb 2014 with - 100mm layer of EME (315t) - 150mm layer of DG20 (350t) with C600 7

8 EME placement French EME specification SAMI binder Local aggregates & filler 315 tonnes of EME Placing of strain gauges in pavement 15 No natural sand, no lime Standard paving equipment Density easily achieved EME being paved and compacted Whinstanes, Brisbane 16 8

9 17 Transfer of EME to Australia 5. Develop test methods & criteria to suit Australian conditions 6. Develop specifications to procure EME 7. Develop structural design guidelines for use of EME 9

10 Conclusion EME Technology Transfer to Australia Produced EME binder in Australia Designed local EME to French standards Demonstrated manufacture & paving Framework established for test methods Draft Austroads EME specification in circulation 19 Thank you 10