Evaluation and life extension of asphalt pavements using rejuvenators and noncollinear ultrasonic wave mixing: A review

Except for the relatively small zones within pavements that are subjected to loadings, the primary challenge in asphalt concrete (AC) pavement design and maintenance is to prevent and/or control environmentally induced distresses. Distresses, including block and thermal cracking, and possibly raveling of construction joints, tend to accelerate with time; as a result, it is critical to evaluate the state of crack resistance in asphalt pavement surfaces before and after maintenance treatments. A review of the use of noncollinear wave mixing to evaluate oxidative aging of AC pavements, and the used of rejuvenators in oxidized pavements toward extension of pavement life, is presented. The approach requires no core extraction. Results show that the noncollinear wave mixing can evaluate the state of oxidative aging of AC pavements. Results also indicate that the use of rejuvenators is a successful strategy of pavement maintenance and sustainability.