A Case Study: Assessing the Sensitivity of the Coefficient of Thermal Contraction of AC Mixtures on Thermal Crack Prediction

Thermal cracking results in both structural and functional problems in asphalt concrete (AC) pavements. A critical parameter affecting the buildup of thermal stresses that ultimately lead to cracking in AC pavements is the coefficient of thermal contraction (CTC) of the AC mixture. The objective of this study is to assess the sensitivity of CTC of AC mixture on thermal cracking. Values of CTC of AC mixtures were identified through literature review, while other relevant data needed for thermal cracking prediction were obtained for three AC mixtures from the new Mechanistic-Empirical Pavement Design Guide (MEPDG) documentation. Finally, the amount of thermal cracking, in terms of length and percent damage, was predicted using the new (MEPDG) software. Results showed that the sensitivity of CTC of AC mixtures on thermal cracking is highly material dependent. The greatest sensitivity was observed with medium strength and ductile AC mixture.