Blending Charts Based on Performance-Graded Asphalt Binder Specification

Abstract

Blending charts are used to predict properties of blended asphalt binders (mixture of an asphalt binder with other asphalt binders or modifiers) on the basis of properties of its components. These charts can be used to produce specific grading asphalt binder with blending available materials. In addition, they are used to select proper type and amount of asphalt binder or recycling agent in the design of recycled asphalt mixtures. Current blending charts are based on traditional asphalt grading parameters, such as viscosity and penetration. With the expansion of use of the SUPERPAVE system for design of asphalt mixtures, it is necessary to develop new blending charts based on performance-graded (PG) asphalt binder parameters. The main objective of this research was to characterize blended binders with the PG testing parameters, such as G* (complex shear modulus), δ (phase angle), S (stiffness), and m-value (creep rate). Ten different blended asphalt binders were characterized with the PG grading system. A linear relationship was found accurate enough for prediction of PG parameters of blended binders with proportion of new asphalt binder or recycling agent in blends. Two types of blending charts can be used on the basis of PG performance criteria or temperatures at which PG criteria were satisfied. The findings can be used for selection of recycling agents for asphalt recycling projects and for producing specific PG binders by blending available asphalt binders.