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
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Effect of Morphology on High- Temperature Rheological …/12... · • A quantitative morphological parameter for PMB, i.e. the characteristic wavelength ξ by 2D-FFT method. •
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Workshop Swedish Node in Nordic Research School for Pavement Engineering
Jiqing Zhu Swedish National Road and Transport Research Institute (VTI)
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
Zhu J. | Effect of Morphology on High-Temperature Rheological Properties of Polymer-Modified Bitumen | 3
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
Zhu J. | Effect of Morphology on High-Temperature Rheological Properties of Polymer-Modified Bitumen | 4
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
Zhu J. | Effect of Morphology on High-Temperature Rheological Properties of Polymer-Modified Bitumen | 5
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
Zhu J. | Effect of Morphology on High-Temperature Rheological Properties of Polymer-Modified Bitumen | 6
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).