Stability and rheology of asphalt-emulsion under varying acidic and alkaline levels

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Department of Civil and Environmental Engineering


Asphalt-emulsion is a cleaner material in pavement constructions, which can substantially reduce energy consumption and emissions. Stability and rheology are critical issues in the applications of asphalt-emulsion. Asphalt-emulsion CSS-1h, used in this study, is a cationic slow-setting emulsion. Stability and rheology are, to some extent, determined by the interactions of asphalt and water in asphalt-emulsion. The objective of this study was to investigate the interactions of asphalt and water in asphalt-emulsion under different acidic and alkaline levels, which are reflected in the stability and rheological behaviors of CSS-1h. In order to achieve this goal, the original CSS-1h was mixed with the contents of hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions and then measured to determine its moisture retention during oven heating for characterizing the emulsification stability under different acidic and alkaline levels. The Dynamic Shear Rheometer (DSR) experiments evaluated the apparent viscosity of asphalt-emulsions and the rutting indicator of their residues. In addition, the microscopic properties of the asphalt-emulsions were characterized using the Fourier-Transform Infrared Spectroscopy (FTIR). The FTIR analyzed the influence of acidic and alkaline levels on the microscopic properties of CSS-1h using molecular chemistry. The results concluded that the acidic and alkaline levels have significant effects on the functional groups in asphalt-emulsions and their residues, as well as on the interactions of asphalt and water, which in turn affects the stability and rheology of the cationic asphalt-emulsions.

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Journal of Cleaner Production