There are two processes of adding crumb rubber modifier (CRM) to hot mix asphalt (HMA),
that is, the wet process and the dry process; and different technologies are available for
each process. On the basis of the results of the binder study and producer's practices, HMA
specimens were prepared using two selected AR binders with Producer R and A CRMs for
Rhode Island (RI) dense-graded and dense-graded friction course (DGFC) mixtures,
respectively. Aggregates procured from four local asphalt contractors were used. In addition …

There are two processes of adding Crumb Rubber Modifier (CRM) to Hot Mix Asphalt (HMA),
ie, the wet and the dry process; and different technologies are available for each process. In
this study, Asphalt Rubber (AR) binders were prepared by combining CRM obtained from
three sources and three grades of asphalt cement (AC-5, AC-10, and AC-20) typically used
in Rhode Island using the wet process. Further, to investigate the effect of CRM amount and
additives, AR binders were prepared with two or three percentages of CRM and three levels …

This is the final report of the research project, entitledViable Use of Crumb Rubber for
Highway Construction in Rhode Island.This study dealt with the investigation of the means
by which the State of Rhode Island can effectively comply with the mandate of the Section
1038 of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) to use recycled
rubber in asphalt pavements. More specifically, this laboratory investigation characterized
Hot Mix Asphalt (HMA) with Crumb Rubber Modifiers (CRM).