Composition Optimisation of Selected Waste Polymer-Modified Bitumen

Area of Science:

• Materials Science
• Chemical Engineering
• Civil Engineering

Background:

• Waste plastomer disposal presents a significant environmental and economic challenge.
• Bitumen modification with polymers can enhance pavement performance and material durability.

Purpose of the Study:

• To investigate the implementation of polypropylene (PP) and polyethylene terephthalate (PET) into bitumen.
• To analyze the influence of mixing process factors on the properties of modified bitumen.
• To optimize the modification process for bitumen 70/100.

Main Methods:

• Plastomer-modified bitumen was prepared using PP and PET with two bitumen types (20/30 and 70/100).
• Characterization included penetration, softening temperature, cohesion energy, Fraass temperature, and multiple-stress creep recovery (MSCR) rheological testing.
• Experimental design (Plackett−Burman) and generalized Maxwell model were used for analysis. Microstructural analysis was performed using epi-fluorescence microscopy.

Main Results:

• Plastomer-modified bitumen exhibited a fine-grained structure (<10 μm particle size).
• Creep susceptibility (Jnr) was significantly influenced by polymer type, particle size, rotational speed, and bitumen type.
• Particle dispersion depended on rotational speed, plastomer particle size, and mixing temperature.

Conclusions:

• The study successfully optimized the modification process for bitumen 70/100 using fine-grained PP.
• Achieved modified bitumen properties closely matched those of commercial polymer-modified bitumen (PmB 45/80-55) under specific conditions (160 °C, 6300 rpm, 105 min).
• This research offers a sustainable approach to waste plastomer utilization in road construction.