Statistical analysis of the influence of RAP and mix composition on viscoelastic and fatigue properties of asphalt mixes

This study aims at understanding from a statistical point of view the influence of several mix constituents on mechanical properties of asphalt mixes produced with RAP material. The study is developed in two steps. The first section is focused on the qualitative evaluation of the effect of varying certain mix design parameters (aggregate and filler nature, binder content and type) on mechanical properties of mixes containing 20 % of RAP material. Results of the statistical analysis showed that changes in binder nature and binder content have a statistically significant influence on complex modulus of mixes. The second section aims at quantitatively estimating the influence of RAP material content and fresh added binder penetration grade on complex modulus and fatigue life of mixes. Proposed quadratic models satisfactorily fitted experimental data, although some coefficients were not estimated as statistically significant by the software. Observed fatigue and complex modulus performances of mixes containing up to 60 % RAP material are quite encouraging from technical, economical and environmental points of view.