Effect of asphalt binders with identical PG grading from different suppliers on the laboratory performance of asphalt mixture

Abstract

Bituminous binders have significant effect on the overall performance of the asphalt mixtures, although binders are not the main component of the asphalt mixture (4–6% by weight). This paper presents an overview of research efforts undertaken to evaluate the sensitivity of asphalt mixture performance to the change of the binder suppliers in the State of Arizona. The binders used in the asphalt mixture have identical Performance Grade (PG). However, the binders were from different suppliers. The laboratory testing program included the dynamic modulus and the repeated load/flow number tests. Asphalt mixtures were collected from four sections on a project constructed in northern Arizona. This project was unique in that all four asphalt concrete mixtures had the same aggregate structure and source but used PG 76-16 binders obtained from four different suppliers. Based on the test results, the tests were sensitive to variations in the properties of the same PG binders obtained from different suppliers. This was also confirmed through statistical analysis and comparison with the binder test data. In order to assess the sensitivity of the four asphalt binders on the pavement performance, the binder and mixture data were input into the Mechanistic-Empirical Pavement Design Guide (MEPDG) and design simulations were run to compare rutting and fatigue cracking associated with each of the four PG76-16 binders included in this study. Significant statistical differences in both distress mechanisms were also observed for the different mixtures with changing only the binder supplier.