EME2 Pavement and mix design Laszlo Petho, Pavements Manager Fulton Hogan
Outline What is EME2 high modulus asphalt? Performance based mix design and Australian EME2 specification limits EME2 pavement design within the Austroads framework EME2 demonstration trials, ongoing monitoring and upcoming projects
What is EME2? Properties: workable stiff rut resistant fatigue resistant moisture resistant. Achieved by: high binder content 6% hard binder: penetration 10-25 pu low air voids content < 6% performance based design method.
Proportion (%) Proportion (%) Volumetrics 100 90 80 70 60 0 41.9 5.0 37.4 71.8 air voids stone Volumetric properties of a typical AC20 mix 50 40 30 20 10 0 46.4 7.7 4.0 41.4 6.8 9.4 11.8 16.4 weight (m/m) volume (%) volume of mortar (%) fine aggregate filler binder 100 90 80 70 60 50 40 30 0 3.0 41.2 36.5 40.4 45.6 66.9 11.0 air voids stone fine aggregate filler Volumetric properties of an EME2 mix 20 10 0 6.7 7.5 22.1 13.4 5.7 weight (m/m) volume (%) volume of mortar (%) binder
History of EME2 Year Specification 1980 Colas innovation (very high performance road base asphalt) 1988 Technical advice (GBTHP) 1992 NF P 98-140 Couches d`assises: enrobés à module élevé (EME) - (first French standard for EME) 2008 NF EN 13108-1, European standard 20+ years of experience performance & 13t axle on the road network in France Airports (A380, B777), ports, very heavy loads EME2 5
History of EME2 Property GB2 GB3 GB4 EME1 EME2 E (MPa) 9000 9000 11000 14000 14000 Ɛ6 (microstrain) 80 90 100 100 130 Binder stiffness (pen) Binder content (%) Pavement thickness (mm) Time Source: Based on EME 2 & beyond, Etienne le Bouteiller, International Technical Manager Colas, AAPA International flexible pavements conference, 16th, Gold Coast, QLD. 6
Why EME2? 350 mm base asphalt layer 260 mm EME2 layer GB3 heavy duty EME2 in France asphalt in France 25% reduction of base layer thickness
Binder requirements Property Test Method Unit Limit Value Minimum 15 Penetration at 25 C AS 2341.12 pu 1 Maximum 25 Softening point AS 2341.18 C Minimum 56 Maximum 72 Viscosity at 60 C 3 AS 2341.2 Pa.s Minimum 900 Loss on heating AGPT/T103 % Maximum 0.5 Retained penetration 2 AS/NZS 2341.10, AS2341.12 % Minimum 55 Increase in softening point after RTFO treatment AS/NZS 2341.10, AS 2341.18 C Maximum 8 Viscosity at 135 C AS2341.2, AS2341.3, AS2341.4 or AGPT/T111 Pa.s Minimum 0.6 Matter insoluble in toluene AS 2341.8 % mass Maximum 1.0 Penetration index 4 N/A N/A N/A Report Viscosity at 60 C after RTFO 3 AS/NZS 2341.10, AS 2341.2 Pa.s N/A Report Percent increase in viscosity at 60 C after RTFO test AS/NZ 2341.10 % N/A Report 1 One pu equals 0.1 mm. 2 Retained penetration shall be calculated using the equation: (Penetration at 25 C after RTFO x 100) / (Penetration at 25 C before RTFO). 3 Test shall be performed using an Asphalt Institute viscosity tube. 4 According to Annexure A of EN 13924-2006
Technology transfer Wheel tracking Minimum flexural stiffness modulus Fatigue resistance France Large wheel tracker 60 C and 30 000 cycles Trapezoidal, 2 point bending 15 C, 10Hz Trapezoidal, 2 point bending 10 C, 25Hz 3 strain levels, 18 beams Australia Small wheel tracker 60 C and 30 000 cycles (modified test method) 4 point bending beam 15 C, 10Hz (new test method has been drafted) 4 point bending beam 20 C, 10Hz 3 strain levels, 18 beams (new test method has been drafted) Source: Delorme, J, Roche, C & Wendling, L 2007, LPC bituminous mixtures design guide, Laboratoire Central des Ponts et Chaussees, Paris, France. 9
EME2 mix design criteria Property Test method Unit Limit Value Air voids in specimens compacted by gyratory compactor at 100 cycles AS/NZS 2891.2.2 % Maximum 6 Water sensitivity AG:PT/T232 % Minimum 80 30,000 cycles Wheel-tracking at (60,000 passes) 60 C 5,000 cycles (10,000 passes) Flexural stiffness at 50 ± 3 µe, 15 C and 10 Hz Fatigue resistance at 20 C, 10 Hz, 10^6 cycles 4.0 AG:PT/T231 mm Maximum 2.0 AG:PT/T274 MPa Minimum 14,000 AG:PT/T274 µe Minimum 150
Source: Delorme, J, Roche, C & Wendling, L 2007, LPC bituminous mixtures design guide, Laboratoire Central des Ponts et Chaussees, Paris, France. 11
Eagle Farm, Brisbane
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Pavement design Presumptive values for elastic characterisation Asphalt mix type EME2 Binder type EME binder (15/25 pen) Volume of binder (%) Asphalt modulus at heavy vehicle operating speed (MPa) 10 km/h 30 km/h 50 km/h 80 km/h 13.5 2000 3000 3600 4200 AC20 C600 10.5 1500 2200 2600 3100 Austroads temperature correction suitable for EME2 mixes
Pavement alternatives Pavement thickness comparison
Case study
Control design Σ asphalt = 335 mm No of paving runs = 6 EME2 design Σ asphalt = 260 mm No of paving runs = 4 30 mm 30 mm 10mm OGA (Class 320) 10 mm DGA (A15E) 30 mm 30 mm 10mm OGA (Class 320) 10 mm DGA (A15E) 50 mm 14 mm IAC (A15E) 60 mm 20 mm IAC (A15E) 200 mm EME2 165 mm 20 mm IAC (Class 320) 200 mm crushed limestone 200 mm crushed limestone Infinite sand subgrade CBR 12% Infinite sand subgrade CBR 12% Kwinana Freeway SB widening Armadale Rd to Russell Rd Design traffic: 2.20E+08 ESA Design speed: 90 km/h 19
Technical documents www.aapaqtmr.org www.tmr.qld.gov.au
Summary Validation Extensive laboratory testing Production and demonstration trials Pavement design case studies EME2/benefit Technology transfer, including mix design and pavement design Reduced pavement cost Less paving operations Better solution in constrained environment
Thank you Laszlo Petho Laszlo.Petho@fultonhogan.com.au EME2 mix design PSTS107: http://www.aapaqtmr.org/eme_ws1.html EME2 pavement design Technical Note TN142: http://www.tmr.qld.gov.au/business-industry/technical-standards-publications/technical-notes.aspx Mix design technical background: https://www.onlinepublications.austroads.com.au/items/ap-t283-14 Webinar: http://www.arrb.com.au/previously-recorded-webinars-2015.aspx#1457