1 / 30

Impact of Aggregate-Binder Compatibility on Asphalt Mixtures in Arkansas

This study investigates the effects of aggregate-binder compatibility on the performance of asphalt mixtures in Arkansas. The research evaluates the rheological, physical, mechanical, and chemical properties of asphalt binders and aggregates to develop a database of compatible systems. Various testing methods are used to assess compatibility and make recommendations for future projects. Results show differences in specific gravity, absorption, abrasion resistance, penetration, viscosity, and pH values among different binders and aggregates.

larrotcha
Download Presentation

Impact of Aggregate-Binder Compatibility on Asphalt Mixtures in Arkansas

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EFFECT OF AGGREGATE-BINDER COMPATIBILITY ON PERFORMANCE OF ASPHALT MIXTURES IN ARKANSAS Investigators: Zahid Hossain, Ph.D., P.E., A-State Andrew Braham, Ph. D., P.E., UARK Graduate Assistants: MD Rafiue Islam, A-state David Murphy, UARK Mohammad Najmush Sakib Oyan, A-state

  2. OUTLINE • Introduction • Objectives • Materials • Methodologies • Results and Discussions • Acknowledgements

  3. INTRODUCTION Aggregate-binder incompatibility can be serious durability and performance issues e.g., stripping, brittle mix etc. • Incompatibility of aggregate-binder arises from their some certain chemical and physical properties e.g., acidity, surface free energy, durability (aggregates). • Early failures can be mitigated by selecting appropriate aggregate- binder pair. • Such database will be a valuable guide for ARDOT for their future projects. •

  4. OBJECTIVES Evaluate rheological (e.g., viscosity) and chemical properties of (e.g., polarity and surface free energy) of asphalt binders. • Evaluate physical and mechanical (e. g., absorption and durability) and chemical (e.g., polarity and surface free energy) properties of aggregates. • Evaluate surface ACHM mixes (plant and lab.) with different types of aggregates as well as varying amounts of sandstone (absorptive). • Develop a database of compatible aggregate-binder systems. • Recommend suitable test method(s) to screen incompatible aggregates/binders and make recommendations to ARDOT. •

  5. MATERIALS - BINDER Binder Grade Sources Ergon Asphalt and Emulsion, Inc. Memphis, TN (S1) Marathon Petroleum Corporation Memphis, TN (S2) Coastal Energy Corporation Willow Springs, MO (S3) Ergon Asphalt and Emulsion, Inc., Vicksburg, MS (S4) Holly Frontier Refining & Marketing LLC, Catoosa, OK (S5) Lion Oil Company Memphis, TN (S6) • • • PG 64-22 (B1) PG 70-22 (B2) PG 76-22 (B3) • • •

  6. MATERIALS - AGGREGATE Aggregate Type Aggregate Source Nomenclature Duffield Quarry (Blackstone Construction)– Gum Log Quarry APAC-Central - Jenny Lind, S1S1 Sandstone S2S2 Gravel Mountain Quarries, Bismarck S1N1 Novaculite Redstone Construction - Little Rock Quarry Benton County Stone - Mill Creek Quarry APAC Central - Sharp's Quarry S2N2 S1L1 Limestone S2L2 Martin Marietta - Propst Pit #4 S1D1 Dolomite Vulcan Materials. Black Rock Quarry S2D2

  7. METHODOLOGIES – AGGREGATE AND BINDER AGGREGATES TESTING METHOD Specific Gravity and Absorption DESIGNATION AASHTO T 85 Los Angeles (LA) Abrasion Resistance AASTO T 96 Acid Number (pH) ASTM D 1293 Koc and Bulut (2014), Hossain et al. (2020) ASPHALT BINDERS TESTING METHOD Penetration Test Sessile Drop (Optical Contact Angle) DESIGNATION AASHTO T 49 Rotational Viscometer (RV) AASHTO T 316 Acid Number (pH) Hardee, J. R., (2004) Van Oss et al., (1987), Hossain et al., (2020) Rashid and Hossain, (2016), Hossain et al., (2020) ASTM D 3625 Sessile Drop (Optical Contact Angle) Atomic Force Microscope (AFM) Texas Boiling Test

  8. RESULTS AND DISCUSSIONS (Aggr. Sp. Gr.) • S2D2 and S2S2 had highest and lowest bulk specific gravity, respectively. • Novaculite also had a high bulk SSD specific gravity within test premise

  9. RESULTS AND DISCUSSIONS (Aggr. Absorption) • Overall absorption is less than 2% for all the aggregates except S1S2. This sandstone had absorption value nearly 4%. • Dolomite had least absorption value, while sandstone from Source 1 had highest absorption value.

  10. RESULTS AND DISCUSSIONS (Aggr. LA Abrasion) • Novaculite from Source 1 was found more durable, and Sandstone experienced highest loss in LA abrasion test. • Dolomite also proven to be a durable material for pavement. • In general, all aggregates have loss less than 40% (ARDOT requirement)

  11. RESULTS AND DISCUSSIONS (Binder Penetration) • For Sources 1, 2, 4, and 6, penetration number decreased as binder grade increased. • For Source 5, PG 64-22 seemed very stiff at 25 ͦͦC. • For this source, PG 70-22 binder was found to be very soft.

  12. RESULTS AND DISCUSSIONS (Binder RV) • PG 64-22: Source 2 and 4 had highest viscosities; Source 6 had lowest viscosity • PG 70-22: S1B2 binder had highest viscosity; PG 70-22 binder from other sources had similar viscosities. • PG 76-22: Binders from Sources 5 and 3 had the highest and lowest viscosities, respectively • Besides S5B3 binder, all other binders met Superpave viscosity criterion (<= 3000 mPa.s at 135 ͦC)

  13. RESULTS AND DISCUSSIONS (Binder pH) • All the binders had pH values less than 7 • Source 4 binders were found to be more acidic, and source 6 binders were least acidic. • Overall, pH did not vary significantly with the binders grade except for source 4 binders.

  14. MATERIALS - PLANT MIX

  15. MATERIALS – LAB MIX • Based on the two sandstone mixes • Performance testing for each mix at 40%, 63%, and 86% sandstone ‒ Sandstone replaced with limestone from APAC-Sharp’s • Binder percentages estimated using Asphalt Institute SP-2 (1996)

  16. MATERIALS – LAB MIX BINDER CONTENT • Binder percentages estimated using Asphalt Institute SP-2 (1996) ??∗ (???+ ???) ??∗ ???+ ??? ???= ∗ 100 ???= ???+ 0.8(???− ???) + ?? “Absorptive aggregates may require values closer to 0.6 or 0.5” Absorption Multiplier Trend Used the known binder contents and absorption of aggregate blends to predict this multiplier Limits were placed at 0.8 and 0.5 • 1.2 AI Absorption Multiplier 1 0.8 0.6 y = -0.2196x + 1.0637 R² = 0.8206 • 0.4 0.2 0 0 0.5 1 1.5 2 2.5 Aggregate Absorption (from plant)

  17. METHODOLOGIES – PLANT AND LAB MIX ASPHALT MIXTURES TESTING METHOD DESIGNATION Bulk Specific Gravity AASHTO T 331 Dynamic Modulus & Flow Number AASHTO T 378 & R 84 I-FIT AASHTO TP 124 Tensile Strength Ratio AASHTO T 283 Hamburg Wheel-Track Testing AASHTO T 324 IDEAL-CT ASTM D 8225-19

  18. PLANT MIX RESULTS (Dynamic Modulus) Dynamic Modulus Master Curves 3000 Dynamic Modulus |E*|, ksi 2500 2000 Delta Sharp's Redstone Jenny Lind 1500 1000 500 0 1.0E-06 1.0E-03 Reduced Frequency, (Hz) 1.0E+00 1.0E+03 1.0E+06 • Delta (Dolomite) and APAC-Sharp’s (Limestone) show the highest cracking resistance • APAC-Sharp’s (Limestone) shows the highest rutting resistance

  19. PLANT MIX RESULTS (Hamburg Wheel) Hamburg Wheel Track Testing Number of Passes 0 5000 10000 15000 20000 0 0.5 Delta Sharp's Redstone Jenny Lind Rut Depth (mm) 1 1.5 2 2.5 3 3.5 4 • Each of these mixtures contains anti-stripping agent • Only Redstone (novaculite) features a stripping point of inflection • Jenny Lind (sandstone) and Redstone (novaculite) feature the lowest final rut depths

  20. PLANT MIX RESULTS (Ideal-CT) Ideal-CT (ASTM D8225) CT-Index Mixture: Average: 48.68 32.76 38.21 71.62 Std. Dev.: 18.16 7.85 7.28 7.12 Delta Sharp’s Redstone Jenny Lind • Jenny Lind (Sandstone) shows the highest cracking resistance • Some mixes featured a high variability between specimens

  21. PLANT MIX RESULTS (I-FIT) IFIT Results (AASHTO TP 124): Flexibility Index Mixture: Average: Std. Dev.: Delta Sharp’s Redstone Jenny Lind 1.27 2.55 3.56 6.93 0.41 0.87 3.06 0.83 • Jenny Lind (Sandstone) again features the highest cracking resistance • Redstone (Novaculite) shows a high variability between specimens

  22. PLANT MIX RESULTS (TSR) Tensile Strength Ratio Average Moisture Conditioned Strength 1 0.9 1600 Moisture Conditioned Strength 0.8 1400 Tensile Strength Ratio 0.7 Delta Sharp's Redstone Jenny Lind 1200 Delta Sharp's Redstone Jenny Lind 0.6 1000 0.5 (kPa) 800 0.4 600 0.3 400 0.2 200 0.1 0 0 • Should consider the TSR and moisture conditioned strength • Overall, Redstone (novaculite) shows the highest moisture resistance • Jenny Lind (sandstone) shows the lowest moisture resistance

  23. LAB MIX RESULTS (Dynamic Modulus) Plant Mixes Jenny Lind 63% SS 3000 3000 Dynamic Modulus |E*|, ksi Dynamic Modulus |E*|, ksi 2500 2500 2000 2000 Delta Sharp's Redstone Jenny Lind 1500 1500 1000 1000 500 500 0 1.0E-06 0 1.0E-02 1.0E+02 1.0E+06 1.00E-05 1.00E-03 1.00E-011.00E+011.00E+031.00E+05 Reduced Frequency, (Hz) Reduced Frequency, (Hz) • Similar cracking and rutting potential between Jenny Lind lab mix and plant mix • Further results will show the impact of sandstone levels on dynamic modulus

  24. LAB MIX RESULTS (HAMBURG WHEEL) Hamburg Wheel Track Testing Number of Passes 0 5000 10000 15000 20000 0 2 Jenny Lind (40% SS) Jenny Lind (63% SS) Jenny Lind (86% SS) Rut Depth (mm) 4 6 8 10 12 • No anti-stripping agent present • Mix containing 40% sandstone shows the highest overall moisture resistance • All three mixes featured a stripping point of inflection

  25. LAB MIX RESULTS (IDEAL- CT) CT Index: Mixture Average: 59.47 58.22 46.03 71.62 Std. Dev. 11.96 9.95 5.23 7.12 Jenny Lind, 40% SS Jenny Lind, 63% SS Jenny Lind, 86% SS Jenny Lind Plant-Mix (63% SS) • Each Jenny Lind lab mix showed a lower CT-Index than the plant mix • Lab mixes showed lower CT-Indices for higher sandstone percentages • These results showed high variability

  26. LAB MIX RESULTS (TSR) Jenny Lind 63% SS 1600 1400 Tensile Strength (kPa) 1200 1000 Moisture Conditioned Unconditioned 800 600 400 200 0 • No anti-stripping agent present in mixture • TSR = 68% • Similar unconditioned strength to plant mix • Much lower moisture conditioned strength than plan mix

  27. Ongoing and Future Work • Binders: Surface Free Energy, Atomic Force Microscopy Analysis • Aggregates: Surface Free Energy • Loose Mixtures: Texas Boiling Test • Mixture tests: TSR, Hamburg Wheel, I-FIT, Dynamic modulus, etc. of the remaining samples • Data Analysis and Recommendations

  28. Sanghyun ACKNOWLEDGEMENT • ARDOT for Financial Support • Chun Sanghyun, Project Manager, Ph.D., P.E. • TRC 2102 Subcommittee Members • Suppliers of Binders, Aggregates and Mixtures

  29. MATERIALS - PLANT MIX Plant Binder Grade NMAS Dominant Aggregate Delta PG 70-22 12.5mm Dolomite APAC-Sharp’s PG 70-22 12.5mm Limestone Redstone PG 70-22 12.5mm Novaculite APAC-Jenny Lind PG 70-22 12.5mm Sandstone Blackstone - Duffield PG 70-22 9.5mm Sandstone

  30. MATERIALS – LAB MIX Sandstone Percentage 63% Binder Percentage 5.7% Plant APAC-Jenny Lind** APAC-Jenny Lind 40% 5.72% APAC-Jenny Lind 86% 5.59% Blackstone – Duffield** 86% 5.5% Blackstone - Duffield 63% 5.68% Blackstone - Duffield 40% 5.55% **Lab mix based on the initial design for the given plant mix • Based on the two sandstone mixes • Performance testing for each mix at 40%, 63%, and 86% sandstone • Sandstone replaced with limestone from APAC-Sharp’s • Binder percentages estimated using Asphalt Institute SP-2 (1996)

More Related