Differences in asphalt binder variability quantified through traditional and advanced laboratory testing

The variability in the properties of asphalt binders used for road construction could induce uncertainty in the response, performance, and degradation of flexible pavements. Although in the last 25 years some countries have adopted performance-based classification systems and stricter quality control procedures to reduce the variability of the material during its production, the reality is that most countries-including emerging economies that are extensively investing in road infrastructure-continue using classification techniques based on traditional indexes (i.e. penetration and viscosity). The objective of this paper is to assess the variability of traditional indexes and fundamental properties among eighteen asphalt specimens produced in the same refinery and classified as penetration 60-70 1/10 mm. The results show that the variability of the fundamental properties (i.e. rheological, thermodynamic, and chemical) among specimens is substantially higher than that of traditional asphalt-tests indexes (i.e. penetration, softening point, and penetration index). These results support the necessity for enhancing current classification and production practices in those countries that still use these traditional indexes.