Experimental Evaluation of Thermal Cracking Characteristics of Reclaimed Asphalt Pavement Mixtures

Abstract

Meeting sustainability requirements in asphalt concrete pavements generally requires the process of recycled materials or the employment of energy saving technologies. The most common form of energy saving technology is the pavement recycling. Reclaimed Asphalt Pavements (RAP), which is normally created when existing asphalt concrete surfacing or crushing materials resulting from old asphalt pavements removal. This paper investigates the thermal cracking resistance of RAP laboratory-prepared Marshall asphalt concrete mixtures. The asphalt mixtures were produced with 0%, 5%, 10% and 15% RAP contents. The experimental testing program included Semi – Circular Bending test. The mechanical criteria for the performance of such mixtures against thermal cracking in this research is stress intensity factor.  The effects of different RAP contents on the stress intensity factor of the asphalt mixtures have been mainly investigated.  Moreover, the influences of testing temperatures and rate of loading have been observed. Test results revealed that the inclusion of 15 percent RAP significantly increased the stress intensity factor by 20, 27, and 78.8% for testing temperatures -10, 0, and 10?C respectively. The same trend appears with stress intensity factor at rate of loading (0.5 in/min).