Cracking, Rutting, and Fatigue Performance of Asphalt Mixtures with a Novel Boron Additive

Asphalt binder has a chemically complex structure. Due to this complexity, it is important to enhance the performance properties of asphalt binders by developing new additives that can adapt to their chemical composition. In this context, a new boron-containing additive, cyclic borate ester (CBE), was synthesized in the laboratory. The CBE additive then was incorporated into the asphalt binder at 1%, 2%, 4%, and 6% by weight through mechanical mixing. The asphalt binder with CBE was mixed with aggregate following the Marshall mix design, and briquettes (specimens) were created. For analysis, the Marshall stability and flow tests were conducted on the briquettes, and the Marshall quotient was calculated based on the test results. The indirect tensile test was performed at 5°C, 25°C, and 40°C, with various pulse and rise times. The resilient modulus values of the mixtures were determined using the Asphalt Aggregate Mixture Analyzing System (AAMAS) nomograph. The resilient modulus losses of the mixtures subjected to moisture damage tests also were evaluated using the indirect tensile test. The results showed that the CBE additive improved the stability and strength of the mixtures, reduced the flow values, enhanced low-temperature performance, and increased elasticity, thus minimizing the potential for cracking. Additionally, the additive increased resistance to permanent deformation at moderate and high temperatures, improved load dissipation ability, and enhanced adhesion properties.