Asphalt pavement (or flexible pavement) accounts for a large amount of the road transportation system in Vietnam for its ease of construction and maintenance, and the smoothness it provides to the vehicles while circulating on the pavement. Compared with rigid pavement, asphalt pavement has a shorter service life; thus, more maintenance works are required to ensure the good quality of the pavement. Therefore, understanding the behavior of the material serves as the key point for the appropriate design of the pavement and ensuring a long service life. This paper will present a method for characterizing the linear viscoelastic properties of asphalt mixtures in the time domain, with which deeper insights into the behavior of the material at elevated temperatures can be revealed. The results of this study allow improving the accuracy of the analysis and design of pavement structures and thus the service life of the pavement.