Analysis of rheological properties of rubberized binders containing warm asphalt additives

Abstract

The main objective of using warm mix asphalt (WMA) is to reduce emissions and improve the workability by lowering the mixing and compaction temperatures of asphalt mixes through different mechanisms. Since warm asphalt is a relatively new technology, not much research has been conducted on various mix compositions. While some of the concerns about WMA have been addressed, the interaction of warm mix additives with modified binders, especially crumb rubber modified (CRM) binder, is not known in great detail. This paper presents the data on rheological tests conducted on rubberized binders containing warm asphalt additives. Binders from five different sources were modified using 10% crumb rubber by weight of the virgin binders. Two of the available warm asphalt technologies, Aspha-min® and Sasobit®, were used to produce the warm asphalt binders. From the tests, it was observed that the addition of the warm asphalt additives significantly reduce the permanent deformation of the binders, increase the viscosity at 60 °C and the complex modulus, G*, and decrease the phase angle, δ, at high frequencies and low temperatures compared with the CRM binders.