Laboratory Investigation of Fog-Seal Treatment on Performance of Open-Graded Friction Course Pavement

Abstract

Open-graded friction course (OGFC), also called permeable friction course (PFC), is a thin and permeable asphalt concrete whose skeleton is composed mainly of coarse aggregate, leading to an immediate drainage of water and an adequate frictional resistance, thus reducing traffic accidents and improving driving environments on rainy days. However, high porosity and open aggregate structures may readily contribute to stripping and raveling of OGFC. Application of fog seal on slightly cracked and/or raveled OGFC is one preventive measure to extend its service life. This study quantitively examined the influence of fog-seal application on the OGFC’s behavior, such as water permeability, skid resistance, and raveling susceptibility. Laboratory tests, including the permeability test, texture depth test, and loaded wheel abrasion test, were conducted on samples obtained from the lane and shoulder in a section of OGFC pavement. Results demonstrate that as fog-seal application rate increased, permeability decreased. Fog seal temporarily reduced the texture depth. However, texture depth could be recovered after the loaded wheel test. Obviously, fog seal can play a beneficial role on abrasion resistance, thereby presenting a potential to ameliorate the durability of OGFC pavements.