Assessment of the Rheological and Mechanical Properties of Emulsion–Cement Paste

The main objective of this study was to evaluate the rheological and mechanical properties of emulsion–cement paste (ECP), which is generally formed during the mixing process of cold recycled mixtures. Forty-five combinations of ECP specimens were prepared at varying amounts of emulsion, cement, and water. Specimens were mixed using a low-shear mixer, then allowed to cure in an oven at 60°C for 72 h. The testing program for ECPs included multiple stress creep recovery, bending beam rheometer, linear amplitude sweep, penetration, and isothermal calorimetry tests. Statistical analyses were then conducted to assess the significance of the impact of ECP constituents on the low-, intermediate-, and high-temperature properties. Results showed that varying the proportions of emulsion, cement, and water significantly influenced the properties of ECPs. Higher cement and water contents improved the properties of ECP at high temperatures, but reduced their resistance to intermediate- and low-temperature cracking. Conversely, increasing the emulsion content improved the resistance of ECPs to fatigue and low-temperature cracking, while increasing their rutting susceptibility at high temperatures. The outcomes of this study provide more knowledge about the interactions among emulsion, cement, and water, which can be beneficial to the designers of asphalt mixtures that involve the use of emulsion, cement, and water, such as cold recycled mixtures.