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 degrees 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.

Automated summary

The study evaluated the performance of hot mix asphalt modified with crumb rubber through temperature influence and digestion time between bitumen and rubber. The results indicated a direct relationship between bitumen and rubber interaction with temperature and contact time. At high temperature and long contact time, a significant increase in rubber mass was observed, leading to a decrease in light fractions in bitumen and consequent stiffening. Additionally, FTIR analysis showed only a physical interaction between the components.