Abstract:
The application of concrete pavements that have been practiced for many years in developed countries is relatively new in Turkey. As well as choosing the most appropriate type of pavement, it is important to determine the optimum pavement thickness for the given traffic level, subgrade condition, and environmental factor to minimize the life cycle cost of the structure and protect the pavements. However, in most methodologies, the lack of consideration of the various main factors (such as vehicle loads, loss of support, thermal gradient, or environmental conditions) that produce stress on the concrete pavement prevents accurate calculation of the required thickness. Contributions of structural fibers to the mechanical and durability properties of concrete have been known for a very long time. However, the number of design methods that cover the use of fiber reinforcement in concrete pavements is very limited and all the methods use different approaches. The main objectives of this study are to compare the differences between the thickness design methodologies of AASHTO (1993), IRC SP 46 (2013), and StreetPave v12 (2014) and to emphasize the lack of the methodologies. The thickness design based on three methodologies was carried out for a sample road using material parameters retrieved from the literature. The contribution of fibers with different types (synthetic, steel and carbon) and amounts (0.2-1.0%) to thickness requirement was evaluated by means of different approaches. To see the effects of the concrete matrix on the effectiveness of fibers two types of concrete (RCC and conventional PCC) were considered. The effects of the presence of edge support and dowel bars on the required thickness were also examined. Finally, Turkey's policy on concrete roads were evaluated briefly. The results of the study showed that usage of the appropriate type and amounts of fibers in the well-designed concrete mixture (whether RCC or PCC for this study) provides to use of lower pavement thickness. Also, using concrete shoulder or dowel bar reduces the required thickness.
