Abstract:
In Open Graded Friction Course (OGFC) is a thin permeable layer of special type Hot Mix Asphalt (HMA) which contains a combination of uniform size aggregate skeleton with minimum fines, and high asphalt content. OGFC is being used as an effective pavement material in many countries for expressway construction as it has many positive attributes in performing as a pavement material. During the operational stage of many expressways which were made out of dense asphalt, several issues were observed in wet seasons such as skidding, splash, hydroplaning. OGFC is a suitable solution as a pavement surfacing material for such existing drawbacks. Drainage characteristic of a pavement is one of the important parameters which dominantly contributes to the durability of a pavement. However, the inefficient water drainage due to the lack of drain-ability of vertical drainage caused by the clogging of OGFC lead to observe the properties of lateral drainage. Though, many studies had been carried out to address the clogging effect due to dust particles, no permanent rectification on this issue was found. Therefore, to investigate OGFC in a different way, the lateral drainage characteristics are analysed to identify the water movement on the surface of OGFC by comparing the capacities which can be endured by different types of OGFC. This study analyses the lateral drainage characteristics of OGFC pavement to find out the OGFC gradation which shows the optimum values for the combination of permeability and durability characteristics under the laboratory conditions. Further, the computer image analysis with the aid of MATLAB software is used to analyse the lateral drainage characteristics by identifying and calculating the areas of voids of cross sections captured as 2D photographs by a DSLR camera (Nikon- D3300). The proposed method is less time consuming, comparatively inexpensive and can be utilized to enhance OGFC by integrating with the traditional laboratory experiments.
