Performance-related and rheological characterisation of natural rubber modified bitumen

This paper is motivated by the limited research available evaluating the comprehensive effects of natural rubber bitumen modification (NR) for pavement applications. A detailed laboratory programme was carried out to evaluate the influence of NR on the high-intermediate-low temperature performance, including rheological characterisations and performance-related tests (fatigue cracking, thermal cracking, fracture and permanent deformation resistance). The main findings indicate some beneficial effects of NR on the performance-related response for fatigue and permanent deformation. Additional benefits were observed regarding the fracture strength and the thermal cracking resistance (Delta T-c). The viscoelastic effects of NR produced significant changes in the rheological properties of the base bitumen. Overall, the use of NR at a concentration of up to 7% by weight of bitumen proved to be a reasonable option for use in pavement applications, having more substantial benefits in tropical regions in agreement with its predominant effects on the bitumen modification at intermediate-to-high temperature conditions. (C) 2020 Elsevier Ltd. All rights reserved.