Polymer modified bitumen: Optimization and selection

• Polymer-bitumen blends were manufactured using three different modifiers.
• Experimental design was used to study the effect modifiers on physical properties.
• Optimization of polymer-bitumen blends were proposed based on target properties.
• Materials selection charts for polymer modified bitumens were proposed.

Polymer modification of bitumen has been commonly performed since the 1980s in order to decrease bitumen (and pavement) susceptibility to high and low temperatures, allowing reduction in common failure mechanisms as rutting and cracking. Bitumen modification has been commonly performed by addition of thermoplastic or elastomeric polymers. However, there are just a few studies on bitumen blends using multiple materials, seeking for specific advantages provided by addition of these modifiers. This work describes the results obtained after the preparation of multicomponent polymer-bitumen blends (MC) based on an 80/100 penetration grade bitumen with varying amounts of (i) Polyethylene wax (PW); (ii) Styrene–Butadiene–Styrene copolymer (SBS); and (iii) crumb rubber (CR). Ideal blends depending on the amount of polymer modifiers added were found by using an experimental design procedure. It was possible to propose charts allowing optimizing and selecting appropriate polymer modified bitumens (PMB) depending on target properties for a given application by following Ashby’s materials selection methodology.