Experimental investigation of the oxidative ageing mechanisms in bitumen

Exploring the oxidative mechanisms of bitumen after laboratory short- and long-term ageing

“…The bitumen's exact composition depends on the refinery process and the origin of crude oil, a fact that makes the determination of bitumen chemistry even more challenging [10,11]. Despite these difficulties, it has been proposed that the reaction mechanisms in each bitumen follow two-rate determining oxidation phases: the chemically distinct fast and slow phases [6,12,13]. Initiated by Petersen and his coworkers, recent literature confirmed experimentally the formation of organic carbon-centred radicals, which would be expected in a dual-sequential oxidation scheme [12,14].…”

“…Despite these difficulties, it has been proposed that the reaction mechanisms in each bitumen follow two-rate determining oxidation phases: the chemically distinct fast and slow phases [6,12,13]. Initiated by Petersen and his coworkers, recent literature confirmed experimentally the formation of organic carbon-centred radicals, which would be expected in a dual-sequential oxidation scheme [12,14]. The existence of free radicals will most likely provoke the chemical reactions resulting eventually in the formation of polar sulfoxides from non-polar sulfides and polar ketones (as well as anhydrides and carboxylic acids in smaller amounts) from benzylic carbon moieties [9].…”

Comparative Study of Thermal-Oxidative Aging and Salt Solution Aging on Bitumen Performance

“…According to the factors influencing the aging of bitumen, different aging modes on bitumen are classified, including thermal-oxidative aging, UV aging, and solution aging [ 5 , 6 ]. Among three aging modes on bitumen, thermal-oxidative aging is the most mature and studied by a large number of researchers, and solution aging is a new formation during recent years [ 7 , 8 ]. Thus, a comparison with thermal-oxidative aging would promote the customization of the specifications of solution aging of bitumen.…”

An Attempt to Track Two Grades of Road Bitumen from Different Plants Using Fourier Transform Infrared Spectroscopy

“…Following the literature, FTIR analysis is one of the most effective analytical methods for studying the chemical composition of oil, vacuum residues, and bitumen [ 21 ]. The range from 4000 cm −1 to 400 cm −1 is the interval where the fundamental molecular vibrations of functional groups are displayed in the spectrum as absorption bands [ 14 , 15 , 22 , 23 ]. According to field studies, bands at 2920 and 2850 cm −1 are assigned, respectively, C–H aliphatic asymmetric and symmetric stretching vibrations [ 14 , 17 , 21 ].…”

“…The bands at 1375 and 1455 cm −1 are assigned to the CH 2 groups > 4, CH and CH 2 CH 3 groups. The paraffin structures are especially at the band at 720 cm −1 [ 5 , 22 , 24 ]. Under 1500 cm −1 , known as the fingerprinting region [ 25 , 26 ], is a complex and informative part of the IR spectrum that typifies the molecule under study.…”