A laboratory research on the performance of warm mix asphalt added different natural gum

During the heating and production of hot mix asphalt (HMA) and its application to the field, the volatile toxic components in its contents are released and harm the environment, human and other living things. The high heat energy needed not only increases the cost of HMA production, but also reduces the working efficiency due to the working environment at high temperatures. This situation has led researchers to develop products to provide more environmentally friendly, healthier working conditions and less energy use. Therefore, the warm mix asphalt (WMA) technology, which is more advantageous than HMA has been developed. There are certain benefits can be occurred including protection of environment, and human health, decreasing required energy, therefore saving construction cost as well as improving performance of HMA with the application of WMA technology. However, undesired conditions have occurred in the properties of the bituminous binder modified with WMA additives such as high increase in softening point, low stripping resistance. The scope of this thesis study has been created to contribute to the literature, where various additives are used to eliminate the mentioned problem. Within the scope of the thesis, bitumen with a penetration rate of 70/100 was mixed with Sasobit® (S®), one of the widely used WMA natural additives, at the rate of 1, 2 and 3% by weight of bitumen, and 1% with Pine Gum Wax (PGW). The physical and stripping resistance properties as well as the rheological performance of warm pine gum added Sasobit® modified bitumen (PGWSMB) were demonstrated by standard tests in the SuperPAVE classification system. WMA was prepared for the Stone Mastic Asphalt binder layer with the initial optimum bitumen ratio method defined by the Asphalt Institute. The WMA samples were produced by the Marshall method and analyzed with Marshall Stability (MS) and yield test. Moreover, indirect tensile strength (ITS) test was applied to WMA samples. Finally, an economic analysis has been made for 1 ton of WMA and HMA that can be produced with PGWSMB. The results showed that certain improvement has occurred in the physical and rheological properties of the PGWSMB samples, and certain decrease was observed in the mixing and compaction temperature. Moreover, significant increase in MS and decrease in yield and ITS value of WMA were found. It can be highlighted that including 1% WMP additive to Sasobit® modified can be a solution to the problem of excessive increase in softening point and low stripping resistance. Economic analysis revealed that the pavement can be constructed with WMA at a lower cost of approximately 15%.