23. Pavement Durability And Performance Following are several slides that show the durability and performance of ARFCs. There are many more sections of pavement where ARFCs were placed on AC pavements then where ARFCs were placed on PCCP pavements. Therefore, some of the data shown is for the larger group of AC pavement sections. Even so, several PCCP sections with ARFC overlays are about a decade old and show excellent performance when used there.
24. Compared to a PCCP top surface, an ARFC On a PCC Pavement provides a smoother ride
25. ARFC provides comparable Friction levels to a PCCP surface, reduces the amount of water spray, and provides increased contrast to pavement markings in wet weather
26. Pavements with ARFC experience less rutting compared To those without an ARFC.
27. Pavements having AR as the final surface Cost less to maintain then neat AC surfaces
28. ADOT PMS Data shows most pavements will experience the first crack at approximately 4 years of age. Once initial cracking occurs, AR greatly reduces the yearly increase in cracking.
29. ARFCs perform similarly in terms of Roughness to ACFCs during their early life but perform better during their second half of their life.
31. As the preceding slides have shown, AR incorporated into pavement surfacing provides measurable performance improvement in several areas and comparable performance in the remaining areas. The oldest section of ARFC in Arizona is an overlay of PCCP on I-19 in Tucson. That section was the first of the “modern” ARFCs placed in one lift. Maintenance Costs have averaged less then $100/year Earlier use of ARFCs were a 3-layer system. The I-19 section was placed in 1989 and has received no major maintenance since then and is still serving traffic today. It’s performance is detailed on the next slide…..
The important message is that the line of site has to be broken. Once it is broken there is a 5 dBA reduction. If the line of sight is not broken the mitigation is not effective. So if you can see the noise source, don’t believe the noise mitigation strategy unless it is sheer distance. The other rule of thumb is that once the line of sight has been broken, for each additional 2 ft of wall height the there is a 1 dBA reduction in noise. So the 4 dBA credit we are taking represents about 8 ft in additional wall height.
During the spring of 2002, ADOT attempted to reduce PCCP pavement surface noise by altering the tining procedures used to texture. Previous research suggested that random transverse tining and longitudinal tining produced quieter pavement surfaces than uniformly spaced transverse tining. ADOT replaced the standard uniformly-spaced transverse tining with a uniformly-spaced longitudinal tining and a randomly-spaced transverse tining test sections. The photos above show the three different surfaces. Both roadside and roadway based measurements were obtained at three roadway locations. For the roadside measurements three classes of vehicles were driven by the microphone locations The results are shown in the next figure.