Low Temperature Behavior of HMA and SMA Mixtures/Tas mastik asfalt ve bitümlü sıcak karısımların düsük sıcaklık altındaki davranısı

Low temperature cracks in asphalt concrete pavements are commonly seen in the East, interior, and west interior Anatolian regions of turkey where air temperature falls below -20 °C, or so low that the developed thermal stress exceeds the thermal strength of asphalt concrete and causes cracks. Low temperature cracking reduces the roadway's driving comfort by the increased surface roughness due to fracture, leading to the seepage of melting snow and rainfall water into the subgradethrough the surface cracks and causing loss of bearing capacity). Combined with the disruption caused by traffic loading, low temperature cracking weakens the structural integrity of the pavement and eventually increases roadway maintenance and rehabilitation costs. Low temperature cracking is one of the main reasons for pavement deterioration, ranked as the second factor in roadway maintenance and repair costs in the Northern regions (Figure 1). Stone Matrix Asphalt (SMA) has been widely used in turkey highways, it provides stone-on-stone contact and high asphalt content that can increase a pavement’s durability and resistance to rutting and reduce noise. However, drainage of binder and higher primary costs could be mentioned of its disadvantages. Since there is no consensus about the performance of SMA at low temperature, conducting a comprehensive study with different tests on the performance of Stone Matrix Asphalt at low temperatures would be beneficial. This project aims at characterizing the low temperature behavior of the Stone Matrix Asphalt (SMA) and HMA in terms of gradation type,aggregate and asphalt type. Upon completing this proposed project, low temperature performance of SMA would be investigated, and a significant contribution will be provided to achieve long lasting pavements without frequent maintenance and rehabilitation. It is believed that the research outcomes will contribute to the national and international knowledge considering the fact that there is only a limited study available in the literature on low temperature performance of SMA.