The improvement of pavement performance using asphalt rubber hot mixes

Abstract

The need of a better pavement performance has led researchers to develop new road materials, mainly for the asphalt layers, where the modification of the asphalt is the main example. This modification usually forces the use of polymers and fibers and, more recently, the use of crumb rubber from ground tires, where the modified asphalt is known as asphalt rubber. This asphalt rubber used in asphalt mixtures produces a superior performance if compared to the asphalt mixtures with conventional asphalt. The crumb rubber modification of the asphalts also presents a higher resistance to climatic effects, compared to the other binders. Based on these assumptions, this paper presents the results of the evaluation of mechanical properties, related to the pavement performance, of asphalt rubber mixtures when compared to conventional mixtures. Two types of aggregate were used (pebble and diorites) and two binders utilized (asphalt rubber and conventional asphalt). The aging effect due to the asphalt mixture production and compaction was taken into account. The materials performance was evaluated through stiffness, fatigue and permanent deformation tests. Reflective cracking performance was also predicted using a mechanistic-empirical method.