Comparison of Chemical and Microstructural Properties of Virgin and Reclaimed Asphalt Pavement Binders and Their Saturate, Aromatic, Resin, and Asphaltene Fractions

Abstract

The chemical properties and microstructural features of two straight-run virgin asphalt binders (PG 52-34 and 58-28) and a reclaimed asphalt pavement (RAP) binder as well as their corresponding saturate, aromatic, resin, and asphaltene (SARA) fractions were examined. Additionally, the properties of the binders with laboratory and plant mixture blending were also observed. Examining the corresponding SARA fractions revealed that the increases in the carbonyl index of RAP relative to the virgin binders were mainly found in the resin and asphaltene fractions, while the increase in the sulfoxide index is mainly found in the asphaltene fraction. The chemical properties were examined using Fourier transform infrared spectrometry. The RAP binder showed a significant increase in the indices of the carbonyl (I CO ) and sulfoxide (I SO ) functional groups compared to the virgin binders. The plant blended binders showed that additional silo storage at the plant increases the carbonyl index. The microstructural features of the binders were examined using environmental scanning electron microscopy (ESEM). The fibril microstructure of the virgin binders was found to be relatively sparse. On the other hand, this microstructure was not visible in the RAP binder, possibly as a result of the severity of the aging, with a severly aged blended binder structure only becoming visible at higher irradiation intensity. The ESEM observation of the resin and naphthene aromatic fractions did not reveal a fibril microstructure as it did in the binders.

Experimental investigation of the oxidative ageing mechanisms in bitumen

“…Considerable research has been devoted to the determination of these functional groups via chemical analysis such as Fourier-Transform Infrared spectroscopy (FTIR) [14,21,22]. When it comes to the fractions of bitumen, previous studies were also limited to the explanation that a sequential reaction, of aromatic to resin and finally to asphaltene fraction, takes place [23][24][25]. No further evidence for the mechanisms behind these changes and the accompanied reasoning has been provided apart from microstructural changes observed with the use of microscopy [26][27][28][29].…”

Reutilization of crystalline waste plastics for modified asphalt using twin‐screw extrusion: Polyethylene and polypropylene as typical subjects

“…Generally speaking, asphalt can be classified into Saturate, Aromatic, Resin, and Asphaltene based on the nature of its composition 31 . The aromatic fraction mainly consisted of polar substances 32 . The interaction between crystalline regions of plastics and the polar components of the asphalt was strong, which improved the component stability of the asphalt.…”

“…31 The aromatic fraction mainly consisted of polar substances. 32 The interaction between crystalline regions of plastics and the polar components of the asphalt was strong, which improved the component stability of the asphalt. This improved the storage stability of the asphalt.…”

Mini-Review on the Application of Nanomaterials in Improving Anti-Aging Properties of Asphalt

“…In terms of asphalt, its characteristics vary in different research. Normally, asphalt consists of saturates, aromatics, asphaltenes, and resins, but different crude oil sources lead to various four fractions ratios. , Therefore, even though two asphalts appeared to be the same grade in different studies, they may be different in nature. However, in most cases, a specific type of base asphalt was adopted to prepare nanomaterial-modified asphalt.…”