The National Academies Press

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From page 6... ... . Permeable Friction Courses are OGFC mixes that are specifically designed to have high in-place air void contents, typically in the range of 18 to 22 percent, for removing water from the pavement surface during a rain event. Read the entire page →
From page 7... ... The "other" category was selected by five agencies with five different factors listed, including safety, winter maintenance, monitor performance, wet weather accident history, and noise reduction. With the exception of Texas, each state that selected the "other" factor also made a selection of one or more of the researchers' presented factors. Read the entire page →
From page 8... ... Only Oregon had a PFC mix design whose maximum aggregate size exceeded 8 Table 1. Design gradation band for Alabama. Read the entire page →
From page 9... ... The majority of the gradation requirements were for mixes whose maximum aggregate size was 12.5 mm or less. Respondents were requested to rank seven aggregate characteristics in order of importance: abrasion resistance, durability, polish resistance, angularity, shape, cleanliness, and absorption. Read the entire page →
From page 10... ... Asphalt Binder Agencies were asked the grade of asphalt binder specified in their OGFCs. Of the 21 states and Austria responding, over 70 percent stated that they specified a PG 76-22 binder. Read the entire page →
From page 11... ... Table 12. Design gradation bands for North Carolina. Read the entire page →
From page 12... ... Only one agency required crumb rubber in the asphalt binder while three others allowed its addition as an option. From the responses given, the overwhelming conclusion drawn is that some type of polymer-modified asphalt binder is specified with OGFC mixtures. Read the entire page →
From page 13... ... There apparently is not a consistency within the agencies on the type of compaction method used with OGFC mix designs. Even with those agencies that have indicated significant use of OGFC mixtures, the method of compaction seems to be split between the Marshall method and the Superpave gyratory compactor. Read the entire page →
From page 14... ... Apparently with the high design voids required for PFCs, most agencies do not consider it necessary to perform any type permeability test; however, approximately one half of the agencies stated that they specified other laboratory tests during mix design. The majority of these tests consisted of the Cantabro Abrasion Loss test or some other type aggregate abrasion test. Read the entire page →
From page 15... ... Figure 3. Respondent ranking for aggregate properties – polish resistance. Read the entire page →
From page 16... ... Responses to what the maximum and/or minimum mixing temperature specified varied among the agencies, but most stated that it was dependent upon the type/ grade asphalt binder that was used. The agencies were equally split on having a maximum silo storage time for OGFC mixtures. Read the entire page →
From page 17... ... , percent air voids, gyratory density and Rice specific gravity. Of these, only draindown, air voids, and Rice gravity were included by more than one agency. Read the entire page →
From page 18... ... Further information on rumble strips can be found in NCHRP Synthesis Report No. 191 published by the Transportation Research Board (2) Read the entire page →
From page 19... ... The majority of the construction has been in the warmer regions of the country and therefore all issues associated with winter maintenance may not have come to light. Typically milled shoulder rumble strips are placed at least 18 in. Read the entire page →
From page 20... ... These performance characteristics were improved wet weather friction, reduced splash/spray, smoothness, noise reduction, reduced hydroplaning, improved nighttime visibility, and improved wet weather visibility. Assigning the point values in order of importance that had been given to the respondent and the rankings assigned by the respondents, improved wet weather friction was considered the most important performance characteristic of OGFC pavements with reduced splash/ spray and reduced hydroplaning tied for second most important (Figures 8 through 12) Read the entire page →
From page 21... ... Two agencies indicated that they perform noise testing of some type. Only two agencies stated that they had conducted life cycle cost analysis for OGFC pavements. Read the entire page →
From page 22... ... (25 mm) ; however, thicker lifts are sometimes specified in the United States and internationally for PFC layers. Read the entire page →
From page 23... ... Respondents were asked to rank seven performance characteristics related to OGFCs. Of these performance characteristics, wet weather friction was identified as the most important performance characteristic. Read the entire page →

From page 6...

... . Permeable Friction Courses are OGFC mixes that are specifically designed to have high in-place air void contents, typically in the range of 18 to 22 percent, for removing water from the pavement surface during a rain event.