Optimal design of mechanical performances of asphalt mixtures comprising nano-clay additives

Abstract

To sustain the life of flexible pavement materials, the quality of the binder needs to be modified and improved. The purpose of the current research is to investigate the optimum mechanical performances, Marshall characteristics, and moisture damages of hot asphalt mixtures containing nano-clay (nC) additives. Three nominated contents of nC additives of 3, 5, and 7% of the hot asphalt weight were combined by a shear blender at 4,000 rpm for 45 min at 150 ± 5°C. Significant mechanical tests were carried out to estimate the modified asphalt mixture characteristics, such as Marshall stability and moisture susceptibility. Mechanical test results showed that the use of nC as an additive was suitable for enhancing the main characteristics of hot asphalt mixes. Generally, it was found that the indirect tensile strength ratio and stability values of the asphalt mixtures containing 3, 5, and 7% of nC were improved by 8, 23, and 24% and 12.5, 40, and 52%, respectively. The 7% nano-clay additive showed superior values of tensile strength and stability as compared with all asphalt mixtures (i.e., 94% and 15.8 kN, respectively).

Keywords

• nano-clay
• marshall stability characteristics
• moisture susceptibility