Rheological characterization of bitumen modified with waste nitrile rubber (NBR)

• Experimental study of the characteristics of modified road bitumen with waste nitrile rubber (NBR).
• Effect of mixing time and NBR content are assessed.
• Good workability characteristic for all tested mixes (various quantities of NBR).
• Improvement of the rheological characteristics at high in service temperature.

This paper presents the results of a laboratory experimental study which evaluates the characteristics of modified road bitumen with waste nitrile rubber (NBR) from shoe sole at high in service temperature. After a characterization of waste nitrile rubber, different blends were processed by varying the waste NBR content and time mixing. The characteristics associated with the manufacture namely viscosity at 135 °C and storage stability were assessed. The rheological characteristics were measured by standard tests such as dynamic mechanical methods using dynamic shear rheometer (DSR). The measurements show a good workability characteristic for all samples tested and an improvement of the rheological characteristics as a shear, storage modulus, tan δ and rutting resistance criterion at high in service temperature especially for the sample with higher content in waste NBR which represent an interesting result from an environmental point of view.