Performance and overall evaluation of nano-alumina-modified asphalt mixture

Abstract

The performance of asphalt mixture affects the service of pavement. Nano-alumina was employed as asphalt mixture modification to improve pavement performances. Properties of asphalt mixtures including high-temperature properties, low-temperature properties, water stability properties, and fatigue properties were investigated through rutting tests, dynamic creep tests, low-temperature bending tests, indirect tensile tests, Marshall stability tests, freeze-thaw splitting tests, and indirect tensile fatigue tests. Considering the various performance of nano-alumina-modified asphalt mixture, the optimization decision was made based on 21 sets of performance data, and the optimal dosage of nano-alumina was further clarified. The results demonstrate that nano-alumina improved all properties of asphalt mixtures, except for low-temperature properties. The decision revealed that the performance of the modified asphalt mixture was the most balanced when the content of nano-alumina is 9%. When the optimal dosage of nano-alumina was 9%, the dynamic stability of the asphalt mixture at 60°C was increased by 34.2%, the cumulative permanent strain was reduced by 36.5-49.5%, the water stability performance was improved by 8.3-19.5%, and the fatigue performance was improved by 3.8-7.2%. However, the low-temperature flexural tensile strain was reduced by 2.1% but still meets the specification requirements. Nano-alumina can be used to modify asphalt pavement materials in high-temperature and rainy areas.