A methodology for characterization of low-temperature fracture behavior of paving mixtures is presented. The critical elasto-plastic energy release rate, the J_Ic parameter, is adopted as the fracture criterion. The methodology permits the study of fracture in plasticized sulfur (Sulphlex) and asphaltic paving mixtures. To accommodate special fracture characteristics of pavement materials, certain modifications to the standard ASTM fracture testing procedures are proposed. The rationale for these modifications is also discussed. Approximate values of K_Ic, K_Q, are correlated to the J_Q measurements, which are a provisional representation of J_Ic, and results are compared with theoretical predictions. Tearing modulus is also investigated. The overall results of this study indicate that the J_Q parameter can be effectively utilized for characterization of thermal cracking susceptibility of pavement materials.