PETROLEUM SCIENCE AND TECHNOLOGY , VOL. , NO. , – https://doi.org/./..
Gene expression programming-based viscosity-mixing rule for asphalt blends Abhary Eleyedatha and Aravind Krishna Swamy
b
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a Indian Institute of Technology Delhi, New Delhi, India; b Indian Institute of Technology Delhi, Civil Engineering, Hauz Khas, New Delhi, India
ABSTRACT
Mixing rule plays a significant role in the prediction of resultant viscosity of asphalt/oil blends. This work presents a novel gene expression programming (GEP)-based approach to obtain a viscosity-mixing rule. To develop these expressions, two distinct binary blends comprising of varying proportion of unmodified binder and polymer modified binder were prepared and tested for their resultant viscosity at different temperatures. The obtained data were used to (i) develop the GEP-based viscosity-mixing rule and (ii) calculate resultant viscosity with viscosity-mixing rules reported in the literature (like the Arrhenius model). Statistical analysis indicated that the accuracy of GEPbased mixing rule is superior over other viscosity-mixing rules reported in the literature.
KEYWORDS
artificial intelligence; asphalt; binary mixtures; bitumen; diluent; gene expression programming; statistical analysis; viscosity; viscosity-mixing rule
1. Introduction It is well-accepted fact that blending of distinct hydrocarbons is a major process in petroleum and asphalt industry. One such example can be the addition of diluent (like toluene, benzene, and naphtha) to heavy oil (like Athabasca oil sand and Orinoco oil sand). These diluents are added to decrease the viscosity and density of the resultant blends. Such an exercise of dilution helps in easy transportation of heavy oil (Baghban, Abbasi, and Rostami 2016). A second example can be the addition of oil/virgin asphalt to recycled asphalt pavement (RAP) mixtures. Typically, aged asphalt binder present in RAP has higher viscosity. To compliment aged asphalt with lighter fractions (that are lost during aging process), virgin asphalt/lighter oil fractions are used as rejuvenators. The third example can be polymer modification of asphalt binder. Polymer modification has been used by paving industry to improve stiffness, usage in heavily trafficked roads, push non-Newtonian behavior boundary (Anjan kumar, Murali Krishnan, and Veeraragavan 2008; McNally 2011). Since these individual hydrocarbons in these binary blends have distinct physical and chemical properties, it is natural to expect that physical and chemical properties of resultant blend will be different than that of individual hydrocarbons. Apart from the viscosity of each component in the mixture, the resultant viscosity of the blend will depend on other parameters like proportion of individual components in the mixture, temperature, pressure, etc. (Mehrotra 1990; Baghban, Abbasi, and Rostami 2016). Researchers have used an API gravity value to model viscosity–temperature relationship for oil mixtures and toluene– bitumen mixture (Sánchez-Minero et al. 2014; Centeno, Sánchez-Reyna, and Ancheyta 2015). To model the interaction between individual components and resultant viscosity of binary blends, viscosity-mixing rules have been proposed by various researchers. These viscosity-mixing rules range from traditional closed form equations to recent artificial intelligence-based techniques. The traditional CONTACT Dr Aravind Krishna Swamy
[email protected] Indian Institute of Technology Delhi, Civil Engineering, Hauz Khas, New Delhi , India. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lpet. © Taylor & Francis Group, LLC
