Effect of the construction process on the performances of asphalt paving mixes with crumb rubber from scrap tires

This paper presents the results of an experimental study on the use of CRM (CrumbRubber Modifier) in bituminous mixtures for asphalt pavements, using a Dry Process.Employing experimental methods capable of ensuring that the mixtures obtained andthe stress conditions that they undergo in pavements are representative, we clarify someaspects relating to the design and production of mixtures; we also show the effects ofthe bitumen-rubber interaction on mechanical performances (fatigue resistance andrutting). Among the various factors involved in manufacture, a particular investigation was carriedout on the effects of asphalt content, mixing temperatures and mixture compaction.The experimental results show that the addition of rubber to bituminous mixtures witha Dry Process has effects on the physical and mechanical properties of bituminousmixtures that are similar to those given by the use of polymer-modified bitumens (thermoplasticelastomers, SBS type).