A Fracture Energy Approach to Model the Thermal Cracking Performance of Asphalt Rubber Mixtures

作者：Zborowski Aleksander^*; Kaloush Kamil Elias

来源：Road Materials and Pavement Design, 2011, 12(2): 377-395.

DOI：10.3166/RMPD.12.377-395

• Thermal Cracking
• IDT Test
• MEPDG
• Asphalt Rubber Mixtures
• Crack Depth Fracture Model

The existing Thermal Cracking Model (TCMODEL) that is currently an integral part of the Mechanistic Empirical Pavement Design Guide (MEPDG) has been shown to adequately predict low temperature cracking of asphalt concrete mixtures utilizing conventional binders. However, test results from several asphalt rubber mixtures in this research study showed that the TCMODEL in the MEPDG falls short in predicting the observed thermal cracking resistance of these mixtures in the field. This paper presents development and findings of a new method for thermal cracking potential evaluation in asphalt mixtures, with a focus on asphalt rubber mixtures. Refinements of the existing IDT test protocol are presented, and a new Crack Depth Fracture Model is proposed to include a fracture energy parameter. The new fracture energy model is evaluated with laboratory test results and rationality corresponding with field observations. The new model proved to be satisfactory in predicting the thermal cracking performance for both conventional and asphalt rubber mixtures. Its use in future MEPDG models is recommended.

• 出版日期2011-6