J. Basic. Appl. Sci. Res., 3(2)838-842, 2013 © 2013, TextRoad Publication ISSN 2090-4304 Journal of Basic and Applied Scientific Research www.textroad.com *Corresponding Author: Nariman Barazi Jomoor, Lecturer, Dept. of Technical Engineering, Payame noor University, Iran. E-mails: narimanbarazi@gmail.com Comparing the Effect of Skid Resistance on Porous Asphalt Mixes and Conventional Hot Mix Asphalt Nariman Barazi Jomoor 1 , Mansour Fakhri 2 , Mahmoud R. Keymanesh 3 1 - Lecturer, Dept. of Technical Engineering, Payame noor University, Iran. 2 - Assistant professor in Road &Transportation Engineering, Dept of Civil Engineering, KN TOOSI University of Technology, Tehran, Iran. 3 - Assistant professor, Dept. of Technical Engineering, Payame noor University, Iran ABSTRACT Nowadays, in order to improve the road safety, the measurement of the rate of skid resistance of surface road is considered as one of the most important factors in design of pavement structure. Because the Open-Graded Friction Course (OGFC) mixes has special gradated combination and suitable surface texture of pavements, it has many benefits such as reduction of pavement noise level, hydroplaning and improvement of permeability in comparison to Conventional Hot Mix Asphalt, so that in the porous asphalt pavements because of producing the necessary friction between tyre and surface texture, Automobiles will not slide and show better resistance even at high speeds and rainy conditions. In this research, a comparative study is conducted between OGFC mixes and Conventional Hot Mix Asphalt in the measurement of the rate of skid resistance. The result indicates that OGFC mixes, because of their open gradated combination and surface texture, have a great effect on skid resistance of pavements in comparison to Conventional Hot Mix Asphalt mixes. KEYWORDS: skid resistance, Open-Graded Friction Course, surface texture, Bitumen modified by SBS polymer. 1- INTRODUCTION In recent years, concepts of pavement design has been developed in such as structural (bearing capacity) of pavement, environmental effects (noise, vibration and water pollution), safety (friction, aquaplaning, water spray and hydroplaning) and hydrological (surface water discharge); requirement has to be considered at the same time. Porous Asphalt pavement is an alternative that believed to be meeting the entire above mentioned requirement. Either, the increasing of life time of road pavement with the operating of resisting asphalt mixes against temperature changes, heavy traffic of vehicles and provision of resisting asphalt surface against skidding along with providing safe traffic are also considered as factors of design of these mixes. Operation of Hot mix Asphalt (even with dense graded) in the mentioned ways, particularly in warm climate, is conducive to deteriorations like rutting and bleeding. Modifying these deteriorations involves maintenance operation and treatment in short distance of time after operation or even reconstruct of asphalt pavement which will naturally include high project cost. Because Porous asphalt mixes has special gradated combination and suitable surface texture of pavements, it has many advantages such as reduction of pavement noise level, hydroplaning and glare and improvement of permeability in comparison to Conventional Hot Mix Asphalt, so that in the porous asphalt pavements because of producing the necessary friction between tyre and surface texture, Automobiles will not slide and show better skid resistance. Technology of porous asphalt pavement goes back to the late decade of 1950 and the beginning decade of 1960, but the extensive use of it started in the decade of 1980. This kind of pavement has been used in most European countries such as Netherlands, Spain, Belgium, France…, and also in most American states and other countries like Canada, Australia, South Africa, South Korea and Hong Kong. Because of having special gradated combination and suitable surface texture in these kinds of mixtures, pavements made by porous asphalt mixes have skid resistance in comparison to pavements made by Conventional Hot Mix Asphalt. Due to the fact that safety of passenger and vehicles in accidents and reduction of injuries caused by these kinds of accidents have important roles in choosing the kind of pavement, great care should be given to the role of skid resistance in road pavement. 2- SPECIFICATION OF MATERIALS This experimental study was conducted to evaluate the effect of two types of bitumen: SBS (styrene butadiene styrene) polymer modified bitumen and AC 85-100 Bitumen on two different aggregate gradations as well as the properties of OGFC mixtures. A total of four different OGFC mixtures with two 838