Modification Mechanism of Multipolymer Granulated Modifiers and Their Effect on the Physical, Rheological, and...

Area of Science:

• Materials Science
• Civil Engineering
• Polymer Chemistry

Background:

• Polymer-modified bitumen faces production and stability challenges.
• Granular bitumen modifiers offer advantages in handling, storage, and transport.

Purpose of the Study:

• To develop and characterize a multipolymer granulated bitumen modifier using styrene-butadiene-styrene block copolymer, polyethylene, and aromatic oil.
• To investigate the modification mechanism and effects on bitumen properties.

Main Methods:

• Elemental analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy, and fluorescence microscopy were used to analyze bitumen and modifiers.
• Physical, rheological, and viscoelastic properties of bitumen were tested at various modifier dosages.
• Bitumen mixtures were evaluated for dynamic stability, fracture energy, and durability.

Main Results:

• The multipolymer granulated bitumen modifier exhibited optimal cross-linking with bitumen A due to its higher Z_H/C ratio.
• At 20% modifier content, the modified bitumen's properties matched commodity styrene-butadiene-styrene block copolymers.
• Optimum mixing conditions (185-195°C, 80-100s) ensured best dispersion homogeneity.

Conclusions:

• The multipolymer granulated bitumen modifier effectively enhances bitumen properties, offering a viable alternative to traditional methods.
• A 20% dosage of the modifier provides comparable performance to styrene-butadiene-styrene block copolymer modified bitumen.
• The modifier demonstrates good stability and adhesion, meeting technical requirements for asphalt mixtures.