IQALUIT AIRPORT REDEVELOPMENT PROJECT Pavement Design & Construction Challenges Bryan PALSAT, P. Eng. & Jean-Martin CROTEAU, P. Eng. SUMMARY
» Context » Scope of the project » Logistics » Construction activities » Technical challenges CONTEXT – Iqaluit, Nunavut
» Nunavut • Created as a new territory April 1st, 1999 • 2,093,190 km² • 32,000 inhabitants » Iqaluit • Formerly Frobisher Bay • Iqaluit means « the fish » in Inuktitut • First permanent settlement in 1942 • Nunavut’s capital since Dec. 1995 • Became a City on April 19, 2001 • 8,000 residents
SCOPE OF THE PROJECT
» Public-Private Partnership type project • Signed on September 10th, 2013 » Client • Nunavut Government • Client’s representatives: Partnerships British Columbia » DBFO contract • Construction: 4 years (2014-2017) • Operational commitment: 34 years (2014-2047) » Capital investment • Approximately $300M
8 SCOPE OF THE PROJECT
Client’s representative
Design & Build Operation
9 SCOPE OF THE PROJECT
» Buildings • A new 100,000 square feet Air Terminal Building • Combined Services Building to house all airport and safety vehicles » Civil work • Reconstruction of existing Taxiway A • Construction of two new Taxiways (G and F) • Widening of Apron I • Rehabilitation and repaving of runway 16-34 • Expanding parking lots and local access roads
10 SCOPE OF THE PROJECT
Rehabilitation existing surface 310 000 m² with 40 000 m2 of structural repairs
Various extensions 90 000 m²
New terminal 9 500 m² + new service building 4 500 m²
Roads and parking 30 000 m² SCOPE OF THE PROJECT - Video
12 LOGISTICS – Background information
» Key dates • 1943: Creation by USA • 1949: Sold to Canada • 1953: 17-35 Runway • 1957: Paving • 1976: Overlay by Sintra • 1992: Paving and repairs
13 LOGISTICS – Bitumen and tack-coat binder
» Two grades • PG 52-40 – New Construction • 2016 → 1050 tonnes • 2017 → 480 tonnes • PG 52-34 – Rehabilitation • 2016 → 570 tonnes • 2017 → 1550 tonnes » Tack-coat binder » Challenges • Melting operation Question for the audience: What would you have done • Management all empty drums knowing the logistical • 9000 empty drums/year challenges? • 20 containers/year to ship back 2011 CONSTRUCTION ACTIVITIES – 2014-2015 2015 CONSTRUCTION ACTIVITIES - 2016 2016 CONSTRUCTION ACTIVITIES - 2017 2017 TECHNICAL CHALLENGES
» Repairs related to permafrost » Excavation in permafrost » Asphalt mix-designs » Friction measurement » Ride Condition Index (RCI) » Structural Condition Rating (SCR) » Pavement strength verification » Crack sealing » Tack-coat and prime coat TECHNICAL CHALLENGES – Repairs TECHNICAL CHALLENGES – Repairs
»Geophysical investigation (Laval University) TECHNICAL CHALLENGES – Repairs
»Identification of potential ice wedges TECHNICAL CHALLENGES – Repairs
»Identification of potential ice wedges TECHNICAL CHALLENGES – Repairs
»Correlation with surface condition assessment TECHNICAL CHALLENGES – Repairs TECHNICAL CHALLENGES – Repairs TECHNICAL CHALLENGES – Repairs TECHNICAL CHALLENGES – Asphalt mixes
» Binders • PG 52-40 for new construction, and • PG 52-34 for overlays » Aggregates • One source of aggregate (local quarry) • No sand available or washing facility » Traditional Marshall mixes for airports • Challenges • Volumetrics i.e. voids & VMA • Stability • Three mixes needed to be developed TECHNICAL CHALLENGES – Asphalt mixes
» Mixture #LC02005 • New construction, apron extension, taxiways & pavement repairs » Mix-design • 15% of RAP 0-10 mm • 30% of 10-14 mm • 55% of 0-5 mm • 5.1% of bitumen PG 52-40 » Additional testing • TSR: 93,4% > 75% • Rutting 24.2 mm @ 10 000 cycles TECHNICAL CHALLENGES – Asphalt mixes
» 2015 paving work
Pavement repairs
Apron extension & taxiways
Runway first overlay TECHNICAL CHALLENGES – Asphalt mixes
» 2016 paving work
Pavement repairs
Apron extension
Runway first overlay TECHNICAL CHALLENGES – Asphalt mixes
» 2017 paving work
Pavement repairs
In front of the ATB
Runway final overlay APRON EXTENSION TECHNICAL CHALLENGES – Asphalt mixes
» Mixture #SC01500 →Volumetrics issue • Existing pavements →Stability issue →Concerns over communicated voids » Mix-design →Concerns with resistance to deformation • 15% of RAP 0-10 mm • 43% of 5-10 mm • 42% of 0-5 mm • 5,1% of bitumen PG 52-34 » Additional testing • TSR: 93,4% > 75% • Rutting 12,7 mm @ 10 000 cycles • Permeability results = Same as a fine TECHNICAL CHALLENGES – Asphalt mixes
» Additional testing TECHNICAL CHALLENGES – Asphalt mixes
» 2016/2017 paving work
Apron overlay 2016
Apron & taxiways overlay 2017
TECHNICAL CHALLENGES – Asphalt mixes
» Mixture #LC02550 →Concerns over communicated voids • Landside i,e, streets and parking lots →Concerns with resistance to deformation » Mix-design • 15% of RAP 0-10 mm • 10% of 10-14 mm • 39% of 5-10 mm • 36% of 0-5 mm • 4.75% of bitumen PG 52-40 » Additional testing • Rutting deformation: • 6,3 mm @ 10 000 cycles • 8,7 mm @ 30 000 cycles • Permeability results = Same as a fine TECHNICAL CHALLENGES – Asphalt mixes
» 2016/2017 paving work
2017
2016
TECHNICAL CHALLENGES - Riding Condition Index (RCI)
» Pre-overlay / repair runway condition: TECHNICAL CHALLENGES - Riding Condition Index (RCI)
» Challenges in profiling the runway • Access limited to 10 to 15 min windows (not suitable for SurPRO) • If possible full runway coverage » The solution • Shipped an ICC 2-laser profiler and instrumented a local pick-up truck » Collected profile and RCI • Pre-construction • Post – profile mill and overlay • Post – final overlay (profile used for acceptance) TECHNICAL CHALLENGES - Riding Condition Index (RCI)
»Ride Comfort Index (RCI) vs. International Roughness Index (IRI) • Direct correlation where • RCI 7.2 ~ IRI 1.3 m/km • RCI 5.0 ~ IRI 2.7 m/km • RCI 6.0 ~ IRI 2.0 m/km • Target • RCI ≥ 7,2 i.e. less than IRI 1.3 m/km TECHNICAL CHALLENGES - Riding Condition Index (RCI)
» RCI – Pre-construction TECHNICAL CHALLENGES - Riding Condition Index (RCI)
» RCI - Post profile milling and overlay TECHNICAL CHALLENGES - Riding Condition Index (RCI)
» RCI - Post final overlay TECHNICAL CHALLENGES – Pavement strength
» Pavement design to provide Pavement Load Rating (PLR) of 12 » Granular thickness not compliant with design in de-icing area • Design total thickness – 1030 mm • As-build thickness – 960 mm » Measurement of deflection was proposed to verify pavement strength • Benkelman beam measurement program was developed • Reasoning… • Well suited for small areas • Simple logistic (as opposed to other devices) • Well documented method TECHNICAL CHALLENGES – Pavement strength