Tensile Fracture Toughness of Polymer-modified Warm-Mix Asphalt Concretes

The asphalt concrete (AC) is strengthened by modifying its asphalt binder using various polymer(s), and the polymer-modified asphalt (PMA) shows higher stiffness at high service temperature and higher toughness at low service temperatures. The warm-mix asphalt (WMA) is a new technology which is developed to produce it 30-40 degrees C lower temperatures than conventional hot-mix asphalt (HMA) concrete temperatures (165-185 degrees C). In this study, two polymers and two WMA additives were used to prepare polymer-modified WMA concretes. Fracture energy (FE) was measured at 5 temperatures (from +25 to -25 degrees C) to evaluate their thermal sensitivity. The FE was compared with the normal ACs to see the effect of polymer modification and WMA additive. The results showed that the WMA concretes used in this study had higher FE than HMA concretes at -25 degrees C when prepared with the same performance grade binders (PMA), even though they were produced at a relatively lower temperature.