The Impact of Binder Type on Pavement Design: A Comparative Study

Rutting is one of the failure modes in flexible pavements and is associated with reduced pavement serviceability since it results in aquaplaning, reduced skid resistance and increased roughness. Variations in material characteristics influence significantly the rutting resistance of asphalt mixes. Dynamic modulus (E*) is a fundamental property of Hot Mix Asphalt (HMA) and as such it is associated with mix properties, loading time and temperature. Thus, dynamic modulus is a critical input parameter for the computation of the induced stresses and the developed strains within the pavement structure. The present paper investigated the impact of different types of asphalt binders on E* values, as well as on predicted permanent deformation. Three different asphalt binders were utilized for the scope of the investigation: one pure and two modified. A comparative analysis was performed in terms of pavement design varying the thickness of asphalt layer. Analysis results showed that asphalt mixes with modified binder can achieve better performance in terms of permanent deformation compared to those with pure asphalt provided that there is an equilibrium for the increased cost of using additives for the modification.