Physicochemical and pyrolysis properties of SARA fractions separated from asphalt binder

Abstract

To further understand thermal properties of asphalt binder, four fractions, namely saturates, aromatics, resins and asphaltenes (SARA), were first separated from asphalt binder. Then, physicochemical and pyrolysis properties of SARA fractions were characterized. The results indicate that the contents of aromatics and resins in asphalt binder are higher than that of saturates and asphaltenes. The number-average molecular weights show a successive increase trend from saturates to asphaltenes. Saturates and aromatics contain similar bonds or functional groups, and aromatics contain a smaller number of saturated hydrocarbons than saturates. Also, resins and asphaltenes show several similar transmittance peaks in Fourier transform infrared spectroscopy (FTIR) spectra. Saturates, aromatics and asphaltenes contain more saturated hydrocarbons than that of resins. Further, FTIR spectra of saturates and aromatics are more similar to that of asphalt binder. Some chemical compositions, bonds and functional groups are only shown in FTIR spectra of SARA fractions through which asphalt components can be further understood. Furthermore, differential thermogravimetry curves of asphalt binder and its SARA fractions exhibit obvious unimodal characteristics, indicating that their pyrolysis processes are one-step reaction. The residue yield ratios, the temperatures corresponding to initial decomposition temperature, the main decomposition range and the maximum mass loss rate successively increase from saturates to asphaltenes. It is concluded that the thermal stability of each SARA fraction is successively increased from saturates to asphaltenes.

Bitumen surface microstructure evolution in subzero environments

“…Previous studies showed that the IR spectra of the SARA fractions have high similarity (Zhang et al ., 2015), but their concentrations are different at the bitumen surface microstructures (Masson et al ., 2007). The straight vertical line (Fig.…”

“…5G). IR peak values of 1030 cm −1 are attributed to the sulfoxide functional group (Gong et al ., 2017), which are present in resins and asphaltene fractions (Zhang et al ., 2015).…”

“…Bitumen behaves like a Newtonian fluid above its melting point and as a viscoelastic material below it (Lesueur et al ., 1996; Lesueur, 2009). It consists of four main hydrocarbon fractions, saturates, aromatics, resins and asphaltenes, each having different physiochemical and thermal properties (Zhang et al ., 2015). These are termed SARA fractions, based on increasing molecular weight and molecular polarity (Claudy et al ., 1991; Speight, 1999; Masson & Polomark, 2001; Masson et al ., 2002; Masson et al ., 2006; Zhang et al ., 2015; Shi et al ., 2017).…”

Effects of Aluminum Hydroxide and Layered Double Hydroxide on Asphalt Fire Resistance

“…As one kind of inorganic flame retardant, hydroxides have the merits of non-toxicity and environmental friendliness [ 9 , 10 , 11 , 12 ]. The initial decomposition temperature of both the light components in asphalt and aluminum hydroxide (ATH) is 200 °C [ 13 , 14 , 15 ]. Therefore, ATH can be used in asphalt to enhance its fire resistance.…”

Investigation of moisture susceptibility of SBS modified asphalt containing Alumina Trihydrate by static contact angle measurements

“…Previous studies have been conducted to study ame-retardant properties, including the ameretardant performance [18,19], the aging characteristic of ame-retardant asphalt [20], the design method of asphalt mixture [21], and the e ect of ame retardant on the pavement performance [2,22]. In addition, the thermal gravimetric analysis and infrared spectrum (IR spectrum) were also carried out to determine and analyze the thermal degradation behavior of Flame-Retardant (FR) asphalt materials [23][24][25]. In short, most of the FR asphalt tests have been carried out to analyze the properties of rheological behaviors, pavement performance, and reaction mechanism.…”