Evaluating the influence of design asphalt content to cracking resistance of hot mix asphalt

Cracking resistance is one of the critical properties of hot mix asphalt (HMA) pavements. To mitigate cracking failures and enhance the durability of HMA pavements, it is essential to design an asphalt content that adequately coats the aggregates and ensures long-term adhesion. This study presents an initial assessment of the cracking resistance of dense-graded hot mix asphalt with a nominal maximum aggregate size of 16 mm (BTNC16). The Indirect Tensile Strength Test (ITS) and the Indirect Tensile Asphalt Cracking Test (IDEAL-CT) were conducted to evaluate the cracking resistance of asphalt mixtures at five different asphalt, content levels: 3.5%, 4.0%, 4.5%, 5.0%, and 5.5%. Test results indicate that the design asphalt content significantly influences the cracking resistance of BTNC16; specifically, increasing the asphalt content from 4.0% to 5.0% resulted in a 2.1-fold increase in ITS values and a 2.5-fold increase in CTindex values.