Comparisons of the Resilient Moduli of Asphalt Mixes Containing Recycled Materials through Empirical and Experimental Methods

Abstract

The stiffness of asphalt mixes is a fundamental property that plays an important role in determining the performance of asphalt pavement under traffic loading. The resilient modulus (stiffness) of asphalt mixes can be either determined using laboratory experiments or predicted through empirical methods based on asphalt components’ properties. This paper characterized the effect of recycled materials including recycled construction aggregate (RCA) and glass on the resilient modulus of asphalt mixes using both an empirical method and a series of laboratory experiments. In addition, the resilient moduli obtained from different methods for different asphalt mixes were compared, and the accuracy and reliability of different empirical methods were discussed accordingly. The outcomes indicated that in cases in which the value of resilient modulus cannot be obtained experimentally, empirical equations cannot well predict the actual resilient modulus. Furthermore, the addition of RCA and glass at a certain amount was shown to improve the resilient modulus of the asphalt mix. This may be attributed to the basic properties of RCA due to its smaller flakiness index and particle shape compared with virgin aggregates. These two parameters significantly affected the final performance of asphalt mixes.