摘要: |
Numerous agencies use Open Graded Friction Course (OGFC) mixtures as the final riding surface on their roadways because of the many benefits such as: reduced hydroplaning, reduced splash and spray, reduced headlight glare, improved visibility, reduced accidents, reduced noise, and surface friction properties. However, there have been some indications that OGFC performance is reduced over time due to the tendency of the surface pores to become clogged, so it was urgent that Nevada Department of Transportation (NDOT) conduct this research since OGFC mixtures cost about 25 percent more than dense-graded mixtures. NDOT constructed two projects for this study. The northern project was on state route 535 in Elko and the southern project was on I-15 east of Las Vegas. At each location a dense-graded mix was placed as a control mix to compare performance of the OGFC mix. A series of laboratory and field tests such as Cantabro stone loss, Hamburg Wheel Track Test for rutting susceptibility, retained tensile strength for moisture susceptibility, permeability, friction, texture, and tire-pavement noise were conducted with mixtures at both OGFC and dense-graded locations. Field testing showed the I-15 OGFC mixture exhibited benefits in permeability, friction, and noise reduction compared to the dense-graded mix and was cost-effective while the SR 535 OGFC applied in an urban setting was not. Based on this study, it is recommended that OGFC not be used in an urban environment or town area. |