New Zealand Airfield Pavement Surface Types – Evaluation, Design, Maintenance and Rehabilitation

1. New Zealand Airfield Pavement Surface Types – Evaluation, Design, Maintenance and Rehabilitation John Marsh General Manager Airports, Beca Infrastructure Ltd 2010 FAA Worldwide Airport Technology Transfer Conference April 20th 2010

2. Beca Group • Multi disciplinary engineering and management consultancy • Founded in 1917 • 2,500 employees • Main groups in New Zealand, Australia and Asia • Proud history of successful airport projects since the 1970’s • Over 70 focused and dedicated airport experts • Current major projects in Auckland, Christchurch, Melbourne, Brisbane, Adelaide, Perth, American Samoa, Marshall Islands and various Defence airfields

3. New Zealand

4. New Zealand

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6. New Zealand

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8. New Zealand

9. Population 4 million 7 international airports, plus many smaller regional ports Auckland 13 million PAX 156,000 movements Christchurch 6 million PAX 136,000 movements Wellington 5.5 million PAX 112,000 movements Variety of aircraft from A380 and B777 to small turboprops and GA Facts and Figures

10. Pavement Surfacing Types

11. Pavement Maintenance Issues • Predominantly flexible asphalt pavements other than concrete at Auckland Airport • Usual range of issues with weathering, ageing, fatigue cracking, bleeding and stripping, groove closure, rutting, fuel damage, concrete spalling and fatigue • Challenges of weather extremes from sub- tropical in the north to cooler temperate and alpine conditions in the south • Range of airfield pavement management systems adopted, from simple inspections to more rigorous pavement management systems

12. Innovation and Sustainability • Lower population and associated economic challenges has led to a culture of innovation and sustainability • Material recycling • Crushed concrete • (RAP) Recycled asphalt pavement • Other fillers considered • Lower grade aggregates • Stabilisation with cement, lime and bitumen • Used in low importance pavements or base layers • Innovative solutions to construction e.g. slab removal • Low energy asphalt mixes

13. Auckland Airport: Concrete Technology • Auckland Airport has over 13 million passengers per year • Concrete pavements originally constructed in the 1960’s • Single Runway 05/23 3,635m (11,925’) long • By the early 1990’s pavements exhibiting fatigue cracks and spalling • Areas of slab replacement completed under displaced threshold • Critical central portion needed a new solution

14. Auckland Airport Main Runway 23L-05R

15. Epoxy Underslab Injection • Methodology developed to form a stiff beam along each free edge of the cracked slab to delay the time until further deterioration • Challenges with open graded scoria subbasecourse • Laboratory trials, dynamic trials and full scale test strips • Deflections reduced by approximately 15% • Over 1,000 slabs have now been injected • >90% success rate • 10 year extension until eventual slab replacement required

16. Epoxy Underslab Injection

17. Epoxy Underslab Injection

18. Modified mining loaders Customised forks Cutting and lifting slabs Less noise and debris 600% productivity gains Expedient Slab Removal

19. Expedient Slab Removal

20. Concrete Thermal Monitoring • Research project to determine cumulative temperature hours to develop required flexural strengths • Laboratory testing programme • Concluded insitu 2000 ºC-hours would be sufficient to develop >4.8MPa (700psi) • Monitoring during construction demonstrated required strength achieved in 48 hours • Early opening of the runway reduced disruption to operations

21. Concrete Thermal Monitoring

22. Christchurch Airport: Asphalt Technology • Christchurch International Airport has over 6 Million passengers per year • Primarily thin asphalt pavement surfacings over unbound gravel base layers and a natural gravel subgrade • Main runway 02-20 with a cross wind runway 11-29 • Annual programme of airfield maintenance • Collaborative approach to maintenance established with an airfield works framework with owner, designer and contractor • Goal is to safely and cost effectively implement the annual pavement maintenance works whilst implementing a number of airfield paving innovations and minimising disruption to airfield operations

23. Environmental Considerations • Environmental objectives set for the project • Meeting CIAL’s environmental goals (the Southern Hemisphere’s first CarboNZero airport) • Use of recycled materials and low energy asphalt on airfield pavements • Minimal impact on airport neighbors • Establishment of Environment Management Plans

24. Sustainable Asphalts • Recycled asphalt pavements • 15% to 30% RAP on shoulders and taxiways • Coolpave ™ warm mix AC trialed over the last 3 years • Combination of both • 50% to 90% RAP in the future?

25. RAP Asphalt Mix Properties • RAP mixes found to be less consistent than traditional mixes • Lower workability and tendency to cool more rapidly • Higher temperatures and softer bitumens have been trialed. • Further evaluation of durability

26. Warm Mix AC Properties • Coolpave ™ technology by contractor Fulton Hogan using LEA Co. System • Placement temperatures under 100ºC (212ºF) • 40% reduced energy, lower emissions and safer • Encouraging results, although lower stiffnesses to date and more compactive effort required

27. Christchurch Airport AC Paving