Investigation of performance properties of modified asphalt by boron-containing organic additive

In this study, a novel boron-containing organic additive, which is completely original, was chemically synthesised in the laboratory condition and its performance features on the asphalt were assessed. The structural characterisation of the synthesised organic additive was investigated using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry (TG) analysis methods. The morphologic structure, modification mechanism and thermal degradation behaviours of modified asphalt binders formed by adding the additive to the asphalt were determined by scanning electron microscopy (SEM), FT-IR and TG analysis. The physical and rheological properties were measured using dynamic shear rheometer (DSR), rolling thin film oven test (RTFOT), rotational viscometer (RV), pressure aging vessel (PAV), bending beam rheometer (BBR) and conventional binder experiments. Mechanical properties of mixtures prepared according to Marshall design were examined by the experiments of Marshall stability and flow, indirect tensile, moisture damage, indirect tensile strength, static creep, dynamic creep, indirect tensile fatigue, and Nicholson stripping. The results indicate that the additive increased the asphalt's consistence, rutting, aging resistance, flexibility, adhesion, loading spreading and fatigue life features and decreased temperature sensibility and cracking tendency at the low temperatures. Statistical analysis of the data obtained from experiments supports those findings, indicating that the best additive ratio to enhance the performance features of asphalt was 6%.