Annotated Literature Review for NCHRP Report 640 (2009)

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255 1.68 McDaniel, R. “Case Study: A Porous Friction Course for Noise Control”. North Central Superpave Center News. North Central Superpave Center. West Lafayette, Indiana. Volume 4, Number 3. Spring 2005. 1.68.1 General This paper overviews the testing completed on a test section of Porous Friction Course (PFC) placed in Indiana in 2003. This test section was constructed concurrently with a section of SMA and conventional Superpave HMA. All three of these test sections were evaluated for pavement noise, friction and performance. All there test section mixes were constructed with steel slag aggregate from the same source and a SBS- modified PG76-22. Also, all mixes were designed for a traffic level of 10-30 million ESALs. The gradation of the mixes were all different (No specific data was given, although a gradation curve was presented), and the PFC and SMA had cellulose fibers added. First noise measurements were taken by the pass-by (CPB) and close proximity (CPX) methods. The results of the testing showed that the PFC mix had the lowest noise levels. The conventional Superpave mix had the next lowest noise levels (CPX test showed 3.6 dB higher than PFC, CPB was 4.2 dB higher than PFC), and the SMA had the largest noise levels (CPX test showed 4.8dB higher than PFC, CPB was 5.0 dB higher than PFC). Next the three test sections were evaluated for friction, surface texture, and splash and spray. The PFC surface texture was visually inspected and evaluated to be more open than the SMA and conventional HMA. The difference in surface texture were confirmed and quantified with a Circular Texture Meter. The frictional properties of the PFC mix were found to be higher than the HMA and SMA as quantified by the International Friction Index. Splash and Spray was only visually observed. Based on these observations, the PFC was significantly better at reducing water on the surface and increasing visibility. Overall, McDaniel concluded that, “PFC may offer an effective and economical way to reduce noise while maintaining, or even improving, friction and visibility.” 1.68.2 Benefits of Permeable Asphalt Mixtures McDaniel mentioned that the PFC greatly reduced splash and spray as compared with the SMA mix. 1.68.3 Materials and Design McDaniel did not discuss materials and design. 1.68.4 Construction Practices McDaniel did not discuss construction practices.