Effect of Morphology on High- Temperature Rheological …/12... · • A quantitative morphological...
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Workshop Swedish Node in Nordic Research School for Pavement Engineering Jiqing Zhu Swedish National Road and Transport Research Institute (VTI) [email protected] Effect of Morphology on High- Temperature Rheological Properties of Polymer-Modified Bitumen September 24 – 25, 2018, Hotel C, Stockholm
Transcript of Effect of Morphology on High- Temperature Rheological …/12... · • A quantitative morphological...
Workshop Swedish Node in Nordic Research School for Pavement Engineering
Jiqing Zhu Swedish National Road and Transport Research Institute (VTI)
Effect of Morphology on High-
Temperature Rheological Properties of Polymer-Modified Bitumen
September 24 – 25, 2018, Hotel C, Stockholm
Zhu J. | Effect of Morphology on High-Temperature Rheological Properties of Polymer-Modified Bitumen | 2
• Background
• Materials and Method
• Results and Discussion
• Summary
Contents
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Background
Material property
Composition
Structure
Processing
• Polymer-modified bitumen (PMB) - Styrene-butadiene-styrene (SBS) copolymer • Studies on PMB morphology-rheology relationship - Mostly used additives: e.g. sulfur, carbon nanotubes - Another angle?
HOT!
SBS modification
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Property Base bitumen Polymer-modified bitumen
Penetration, 25 °C (0.1 mm) 86 56
Softening point, ring & ball (°C) 43.4 77.8
Penetration index -1.8 4.3
Materials • Base bitumen 70/100 Pen. - 8% of saturates, 55% of aromatics, 22% of resins, 15% of asphaltenes • Linear triblock SBS copolymer • Polymer content: 5% by weight
of the blend PMB
Bitumen
Bitumen SBS
Materials and Method
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Materials and Method
• Isothermal annealing of PMB - 2 samples: conditioned at 160 °C & 120 °C for 1h respectively
• Microscopy observation and image analysis - Fluorescence microscopy - 2D fast Fourier transform (2D-FFT)
• Rheological characterization (high-temperature) - Dynamic Shear Rheometer (DSR) - ASTM D7175: Complex modulus (G*) & phase angle (δ) @ (64 °C, 70 °C, 76 °C, 82 °C) × (10 rad/s, 1 rad/s, 0.1 rad/s) - ASTM D7405: Multiple stress creep and recovery (MSCR) @ 76 °C, 70 °C and 64 °C - Linear viscoelastic region & Low shear viscosity
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Results and Discussion - Morphology
2D-FFT
• Power spectrum of imgae 𝑓(𝑟↓1 , 𝑟↓2 )
• 𝐹(𝑘↓1 , 𝑘↓2 ) is the Fourier transform. Its discrete form:
• Characteristic wavelength 𝜉= 2𝜋/𝑘↓𝑚
• 𝑘↓𝑚 is the characteristic spatial frequency (peak).
𝑃(𝑘↓1 , 𝑘↓2 )= |𝐹(𝑘↓1 , 𝑘↓2 )|↑2
𝐹(𝑘↓1 , 𝑘↓2 )= 1/𝑁 ∑𝑟↓1 =0↑𝑁−1▒∑𝑟↓2 =0↑𝑁−1▒𝑓( 𝑟↓1 , 𝑟↓2 ) 𝑒↑−𝑗2𝜋/𝑁 ( 𝑘↓1 𝑟↓1 + 𝑘↓2 𝑟↓2 )
𝑘=√𝑘↓1 ↑2 + 𝑘↓2 ↑2
𝜉 = 0 mm = 0 mm
𝜉 = 2.356 mm = 2.356 mm
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Results and Discussion - DSR
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Results and Discussion - MSCR
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Results and Discussion - MSCR
From EN 16659
Tests@ 76 °C @ 70 °C @ 64 °C
160 °C 120 °C 160 °C 120 °C 160 °C 120 °C
ε1100 0.413 0.454 0.250 0.244 0.136 0.139
ε13200 15.8 16.8 9.32 9.32 4.69 4.99
R100 10.7% 8.4% 46.9% 37.5% 55.5% 45.4%
R3200 4.6% 2.2% 28.8% 13.9% 47.1% 24.3%
Rdiff 56.7% 74.2% 38.7% 62.9% 15.2% 46.6%
Jnr100 3.69 kPa-1 4.16 kPa-1 1.33 kPa-1 1.53 kPa-1 0.605 kPa-1 0.757 kPa-1
Jnr3200 4.72 kPa-1 5.15 kPa-1 2.08 kPa-1 2.51 kPa-1 0.775 kPa-1 1.18 kPa-1
Jnr-diff 27.9% 23.8% 56.8% 64.3% 28.0% 56.2%
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• Linear viscoelastic region (@64 °C & 10 rad/s)
• Low shear viscosity @0.001 rad/s
Results and Discussion - Additional
0.727 0.983
Cross model: 𝜂↑∗ − 𝜂↓∞↑∗ /𝜂↓0↑∗ − 𝜂↓∞↑∗ = 1/1+ (𝐾𝜔)↑𝑚
Test
@ 60 °C @ 70 °C @ 80 °C
160°C 120°C 160°C 120°C 160°C 120°C
Low shear viscosity (Pa·s) @0.001 rad/s
3137 2161 1222 521 469 201
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Summary
Sample ξ G’ @76°C & 1 rad/s R3200 @70°C R3200 @64°C …
160 °C 0 mm 134 Pa 28.8% 47.1% …
120 °C 2.356 mm 36.2 Pa 13.9% 24.3% …
• A quantitative morphological parameter for PMB, i.e. the characteristic wavelength ξ by 2D-FFT method.
• Controlling thermal history is a feasible and practical way to control PMB morphology based on the same material.
• Homogenous PMB tends to store more energy during shearing and reach higher recovery after loading than a binary droplet-in-matrix.
• More results coming soon…
Workshop Swedish Node in Nordic Research School for Pavement Engineering
Thanks for your attention!
September 24 – 25, 2018, Hotel C, Stockholm
Presenter: Jiqing Zhu, [email protected]
Supported by:
