One of the important problems of the road industry is to improve the quality of bitumen used as a binder in the composition of asphalt mixtures. The aim of the work was to obtain and study the change in the composition and rheological characteristics of obtained products of a combined oxidation of a vacuum residue and a crumb rubber (CR). In this paper a new 2-stage combined oxidation of a vacuum residue is proposed: the 1st stage of the oxidation at 180 °C with small amount of the CR (2%) and the 2nd one at 260 °C with large amount of the CR (8%). This made it possible to obtain a road modified bitumen with improved high and low temperature performance: the values of the rutting parameter have been increased at temperatures from 46 °C to 64 °C and the stiffness has been significantly reduced to a temperature of -40 °C. The results of the analysis of the oxidation products by chromatography, nuclear magnetic resonance and infrared spectroscopy showed that unsaturated and sulfur-containing bonds in the rubber structure caused an intensive decrease in the content of oils and an increase in the content of condensed aromatic structures. Increasing the content of the condensed aromatic structures leads to increased high temperature resistance and the elastic rubber polymers have led to low temperature crack resistance.
Combined Oxidized Bitumen: Technology, Chemistry and Properties
Oliviero Rossi C.;
2024-01-01
Abstract
One of the important problems of the road industry is to improve the quality of bitumen used as a binder in the composition of asphalt mixtures. The aim of the work was to obtain and study the change in the composition and rheological characteristics of obtained products of a combined oxidation of a vacuum residue and a crumb rubber (CR). In this paper a new 2-stage combined oxidation of a vacuum residue is proposed: the 1st stage of the oxidation at 180 °C with small amount of the CR (2%) and the 2nd one at 260 °C with large amount of the CR (8%). This made it possible to obtain a road modified bitumen with improved high and low temperature performance: the values of the rutting parameter have been increased at temperatures from 46 °C to 64 °C and the stiffness has been significantly reduced to a temperature of -40 °C. The results of the analysis of the oxidation products by chromatography, nuclear magnetic resonance and infrared spectroscopy showed that unsaturated and sulfur-containing bonds in the rubber structure caused an intensive decrease in the content of oils and an increase in the content of condensed aromatic structures. Increasing the content of the condensed aromatic structures leads to increased high temperature resistance and the elastic rubber polymers have led to low temperature crack resistance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
