Investigating the effects of various reinforcements on the bearing capacity of highway pavement

Generally, in order to increase the road bearing capacity, base and subbase layer thicknesses can be increased. However, this method significantly affects the cost of the road. For this reason, this study examines the effects on cost by providing a more robust road construction by using various reinforcement types. The study consists of two main parts. In the first part, the effects of geotextiles, geogrids, and fiber reinforcements on the bearing capacity of the road and how the soil changes its behavior were examined with California Bearing Ratio (CBR) tests. In the prepared samples, reinforcements were tested in different depths, quantities and combinations, and the most efficient placement method was determined in the soil. In addition, the effects of knitting patterns and surfaces on the bearing capacity of the road were discussed by examining the reinforcements under a microscope. Also, by comparing the performances of the reinforcements with each other, the materials that increase the bearing capacity most were determined. In the second part, an uncoated road is designed according to the flexible road design criteria determined by AASHTO (American Association of State Highway and Transportation Officials), which sets the highway and transportation standards. Base and subbase layer thicknesses were calculated for reinforced and unreinforced conditions and compared. Then, considering the soil and reinforcement costs, the models were evaluated in terms of price and performance. As a result, it was observed that the behaviors changed in different reinforced road model samples, and as the settlement increased, it was determined that the reinforcements significantly increased the bearing capacity of the road and decreased the construction cost by decreasing the required layer thicknesses. Considering the price and performance criteria together, the most efficient results were observed in models reinforced with thin geotextile reinforcement.