73 WATER-BITUMEN EMULSIONS BASED ON SURFACTANTS OF VARIOUS TYPES Ayaz I. Abdullin, Elena A. Emelyanycheva ABSTRACT The proper use of petroleum bitumen as a binder requires the decrease of its viscosity. It can be achieved by melting, dissolution in hydrocarbons (diluents) and emulsification in water. Cationic emulsifiers are currently used in production of bitumen emulsions for road construction. The study of the possibility of using surface-active substances of other classes in order to expand the range of effective bitumen emulsifiers is an actual task. The investigation re- ported focuses on cationic, anionic, nonionic, zwitterionic surfactants tested as emulsifiers for production of bitumen emulsions classified as slow-setting one. The bitumen emulsions viscosity, the decomposition rate and the adhesion to the mineral materials are determined. An increase of the bituminous emulsions decay index is observed with an increase of the studied surfactants concentration. The viscosity of bitumen emulsions decreases with an increase of the surfactants concentration. A transition from the class of rapid-setting bitumen emulsions to that of slow-setting one is observed in case of emulsions based on cationic surfactants. The latter demonstrate the best adhesion proper- ties in respect to the mineral material. Keywords: surfactant, bitumen, emulsion, viscosity, decay index, adhesion. Received 05 March 2019 Accepted 31 July 2019 Journal of Chemical Technology and Metallurgy, 55, 1, 2020, 73-80 Chemical Technology of Petroleum and Gas Processing Department Kazan National Research Technological University 65 Karl Marx Str., Kazan, Russia E-mail: e[email protected] INRTODUCTION The proper use of petroleum bitumen as a binder requires the decrease of its viscosity. It can be achieved by melting, dissolving in hydrocarbons (diluents) and by emulsifying in water [1]. The water-bitumen emul- sions are used in a number of road construction works including a macadam construction, a surface treatment, a production of cold emulsion-mineral mixtures, a cold stored mixtures production, a road pavements patching, a laying of thin pavements protective layers [2]. Bitumen emulsions have a number of indisputable advantages compared to those of the classic bituminous binders used in the hot technologies [3]. The preparation of stable water-bitumen emulsions requires the use of special substances called emulsifiers. Surfactants are applied as such substances. In addition to the emulsifying action, the surfactants stabilize the emulsions dispersion and make them stable during a prolonged storage [4]. The emulsifiers when present in small quantities dissolve in water and help to reduce the interfacial tension between the water and the bitumen, which promotes the stable distribution of bitumen droplets in the aqueous phase [5]. The viscosity, the decay index, the stability, the ad- hesion properties are among the basic properties of the bitumen emulsions [6]. They depend on the properties of the bitumen and the emulsifiers [7] as well as on the emulsification mode [8, 9]. The emulsification efficiency depends on the bitumen composition and structure, the composition and the structure of the surfactant and the emulsification mode [4]. If the resins to oils ratio in the composition of the bitumen is greater than 0.6, and the resins to asphaltenes ratio is within the range from 0.5 to 2.0, the bitumen is expected to be efficiently emulsified. An increase of the resins content leads to an increase of the bitumen surface activity, while an increase of the asphaltenes content has the opposite effect [7]. Currently, the cationic emulsifiers are generally used
WATER-BITUMEN EMULSIONS BASED ON SURFACTANTS OF VARIOUS TYPES
Apr 26, 2023
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