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Reducing Compaction Temperature of Asphalt Mixtures by GNP Modification and Aggregate Packing Optimization
Tianhao Yan1, Mugurel Turos1, Jia-Liang Le1
1Department of Civil, Environmental and Geo- Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA.
Materials (Basel, Switzerland)
|September 9, 2022
Summary
Adding Graphite Nanoplatelets (GNPs) and optimizing aggregate packing significantly lowers hot mix asphalt (HMA) compaction temperatures. Combining both methods offers the greatest reduction in temperature, improving HMA sustainability.
Area of Science:
- Materials Science
- Civil Engineering
- Chemical Engineering
Background:
- Hot mix asphalt (HMA) compaction requires high temperatures (125-145 °C) for binder fluidity and workability.
- High compaction temperatures lead to increased energy consumption, NOx emissions, and accelerated asphalt binder aging.
- Reducing compaction temperatures offers benefits like extended paving windows, longer hauling distances, and reduced environmental impact.
Purpose of the Study:
- To investigate the effects of Graphite Nanoplatelets (GNPs) and optimized aggregate packing on reducing HMA compaction temperatures.
- To evaluate the combined effect of GNPs and optimized aggregate packing.
- To maintain traditional production temperatures while lowering compaction requirements.
Main Methods:
- Three modified HMA mixtures were designed: (1) 6% GNP by binder weight, (2) optimized aggregate packing, (3) combined GNP and optimized packing.
- Gyratory compaction tests were conducted on control and modified mixtures at 135 °C and 95 °C.
- A method based on gyratory compaction was developed to estimate mixture compaction temperature.
Main Results:
- All three modification methods improved HMA compactability, significantly reducing required compaction temperatures.
- The combined approach (Method 3) demonstrated the most substantial reduction in compaction temperature.
- GNP addition (Method 1) showed a greater reduction than aggregate packing optimization (Method 2).
Conclusions:
- Both GNP addition and aggregate packing optimization are effective strategies for lowering HMA compaction temperatures.
- The synergistic effect of combining GNPs and optimized aggregate packing yields the most significant benefits.
- These methods contribute to more sustainable HMA production by reducing energy consumption and emissions.
Keywords:
Graphite Nanoplatelets (GNP)aggregate packingasphalt mixturecompactiontemperature reductionMore Related Videos
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