Preliminary study on the mechanical properties of an asphalt mixture containing RAR modifiers

Abstract

This study is an attempt to investigate a reacted and activated rubber (RAR) compound modifier, which is an elastomeric asphalt extender. This type of material is comprised mainly of fine crumb rubber granules with the addition of an activated mineral binder stabilizer; the compounds are typically introduced into the asphalt concrete mixture as a replacement of the bitumen binder. There are two rationales for the potential use of these modifiers within flexible asphalt concrete mixtures. The first rationale is the potential advantages related to long-term environmental sustainability, as inclusion of these rubber compounds can transform an industrial waste product (rubber tires) into a viable replacement for bitumen within asphalt concrete mixtures. The second rationale is the potential of enhancing various mechanical properties of the asphalt mixtures, such as to provide increased resistance to permanent deformation, enhanced pavement friction properties and/or increased durability and strength of the produced asphalt mixtures. With this mind the objective of the current investigation is to preliminary evaluate the performance of the addition of RAR modifiers into an open graded asphalt wearing course mixture. For the research varying percentages of the bituminous binder are replaced by a RAR modifier with the objective to define the most suitable percentage of RAR to be included within the investigated open graded asphalt mixture in terms of compaction degree and stiffness modulus.