Investigation of crack performance of stone mastic asphalt surface course mixture designed with different material components

Flexible pavement of the highway consists of different layers. The layers that make up the flexible pavement are designed to perform under heavy traffic and adverse weather conditions for the service life of the project. However, cracks that may occur due to these adverse conditions turn into structural deterioration in flexible pavement layers during time. The structural deterioration should be analyzed and permanent solutions found. Semi-circular Bending test is preferred to determine the fatigue strength of flexible pavements under repeated traffic loads. Firstly, aggregates and bitumen were determined and obtained. Secondly, the optimum bitumen ratios of the Stone Mastic Asphalt wearing layer were determined. In the last step, Semi-Circular Bending performance test was applied to the specimens prepared at optimum bitumen ratios according to AASHTO T 393 standard. With these tests, the effects of each different bitumen and aggregate materials on the fracture mechanics parameters of the specimens prepared in the laboratory were tried to be determined. In the "Stone Mastic Asphalt" section of the "Road Pavement" part of the Highway Technical Specification, the fine aggregate used in the design needs to be obtained from the same quarry where the coarse aggregate is obtained and the coarse aggregate needs to be obtained from quarries of magmatic origin. In this scope, the use of sedimentary origin rocks in fine aggregate is proposed as an alternative. In addition, this study will serve as a guideline for the Semi-Circular Bending test, which is not included among the performance determination criteria in the Highway Technical Specifications.