Rheological and chemical properties of bitumen modified with crumb rubber in the dry process

This research aims to evaluate the performance of the hot mix asphalt modified with crumb rubber by the dry process by studying the temperature’s influence as well as the impact of the digestion time between bitumen and crumb rubber. The residual bitumen from the drainage test and the non-modified aged bitumen are then subjected to the dynamic shear rheometer (DSR) tests at different frequencies with different temperatures and to Fourier transform infrared spectroscopy (FTIR) analysis. The results show the bitumen and the rubber interaction is directly related to the temperature and the contact time. The maximum increase in rubber mass observed here is approximately 42% at 195 °C for 120 min of contact. The decrease of the light fractions in the bitumen causes a stiffening of the latter as DSR tests show. Lastly, FTIR analysis indicates only a physical interaction.