Description
This paper investigates the effect of a finer crumb rubber (MRP, 0.075-mm) and a coarser crumb rubber (0.595-mm) on the rheological properties of the asphalt binders, and aggregate packing during compaction of mixtures. The effect of green and reacted binder for 3 different rubber contents (10%, 15%, and 20%, by weight) was also evaluated, and the results showed that higher concentration of rubber will improve the performance of asphalt binders. Three binders with two aggregate gradations (fine and coarse) were selected to investigate the effect of aggregate packing during the compaction of the asphalt rubber mixtures. The imaging processing and analysis system (iPas2) was used to evaluate the aggregate packing of the mixtures; which is directly related to the performance testing parameters (dynamic modulus and flow number) of asphalt mixtures. It is found that size of rubber and its reaction time could have important effects on rheological properties and aggregate packing, and thus performance of asphalt rubber mixtures.
