Onsite Use of Recycled Asphalt Pavement Materials and Geocells to ...

as in Ontario, Canada. The survey revealed an increasing use of RAP across the nation. Figures
2.1 and 2.2 show the number of state departments of transportation that used and permitted a
given amount of RAP in intermediate and surface pavement layers in 2007. Data indicate that the
maximum permitted amount of RAP was not being used on a nationwide basis. NCDOT
conducted the survey again in 2009 and found that approximately half of the states reported more
RAP tonnage use after 2007 (fig. 2.3) (FHWA-HRT-11-021).
A recent survey (AASHTO, 2010) reported that across the U.S., the average RAP content
in new asphalt mixes is around 12-15%. A goal established by NAPA is to increase the average
RAP content to 25% by the end of 2013. Table 2.1 provides a summary of the survey conducted
by the AASHTO regarding the usage of RAP in asphalt bound base and HMA surface for the
construction of pavements by state DOTs in the U.S.
Figure 2.1 Usage and potential of various RAP percentages in the intermediate layer (Source:
FHWA-HRT-11-021)
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