Using the viscoelastic parameters to estimate the glass transition temperature of asphalt binders

Glass transition temperature Tg plays an important role in the complex low-temperature behavior of asphalt binder. It is the characteristic temperature at which asphalt binder changes from viscoelastic state to glassy state. In dynamic mechanical analysis, it is determined as the temperature at which the loss modulus attains its peak. This paper presented an approach for analytically estimating the glass transition temperature using viscoelastic parameters of master curves. To demonstrate this approach, asphalt binders were tested by a dynamic shear rheometer (DSR) at different temperatures using frequency sweeps. The storage modulus and the loss modulus master curves were constructed using a complex modulus model and the visocelastic parameters were determined. After verifying the model's accuracy, the viscoelastic parameters were used to estimate the glass transition temperatures of asphalt binders at different reference frequencies. Then, the calculated glass transition temperatures were compared with measured results from conventional temperature sweeps. The comparison indicated that there was a good correlation between them. The proposed method provided a reliable estimation of the glass transition temperature for asphalt binders. A link between the glass transition temperature and the viscoelastic characteristic of asphalt binders was established.