Influence of ethylene-vinyl acetate on the performance improvements of low-density polyethylene-modified bitumen

Due to the low recyclability and slow degradation in nature, waste polyethylene (PE) represents a negative effect on the environment and its disposal is discordant with the idea of sustainable devel-opment in general. On the other hand, the application of the polymer-modified bitumen is an economical and efficient alternative for improving the performance of asphalt pavements. However, the thermal storage stability of PE-modified bitumen is the main factor that prevents its wider application. The main objective of this research was to investigate the feasibility and to quantify the effect of the addition of ethylene-vinyl acetate (EVA) on PE-modified bitumen. This was achieved by testing the modified bitumen produced with the single mass fraction of PE of 4% and different mass fractions of EVA in the range from 2 to 8%. The experimental program included penetration, softening, ductility, rheological properties in high-and low-temperature range, thermal storage stability and compatibility of phases, environmental scanning electron microscopy, and Fourier transform infrared spectroscopy. The results indicated that the addition of EVA increased the viscosity, complex shear modulus, as well as the elasticity of bitumen. Although the high-temperature behaviour was improved, the behaviour in the low temperature range was practically unaffected. The storage stability and segregation of phases were positively affected to a remarkable extent. The base bitumen and PE interacted only physically, but some particular chemical interaction took place with the addition of EVA. (C) 2020 Published by Elsevier Ltd.