Hot-poured crack sealant is usually used to prevent the intrusion of water into pavement system and, hence, to delay pavement degradation. It is widely accepted that crack sealing is a cost effective routine maintenance that may increase the pavement service life. Current ASTM specifications showed ill-correlation between the selection of crack sealants and their field performance. To clearly understand the mechanical behavior of crack sealants, a constitutive relationship must be described. This paper presents the development of a viscoelastic model using Prony-series expansion to characterize crack sealants mechanical behavior at low temperatures. The model is fitted to creep measurements data obtained using a modified crack sealant bending beam rheometer (CSBBR). A three-dimensional finite element is used to determine the time-dependent deflection at the mid span of the beam. The model is found to be capable of simulating the deflection during the loading and the unloading process for tested sealants.