Investigation of the effect of global warming on the bitumen performance grading of Iran

In recent decades, population growth, increasing urban development, and polluting industries have led to an increase in the production of greenhouse gases and the phenomenon of global warming in various regions of the world. Asphalt pavements, as the main infrastructure of the road transportation system, may suffer failures with high repair costs due to their rheological properties under the influence of this phenomenon. In this study, the Prophet model was used to predict the temperature for the years 1400 to 1421 in three 7-year periods under three optimistic, intermediate, and pessimistic scenarios. The prediction accuracy of this model based on the fitting coefficient was more than R2=0.8 on average. Based on the prediction, the country's demand for bitumen with different functional classifications is then presented in comparison with the available quantities. By predicting and calculating the functional classification of bitumen in 1440 and presenting the results at two confidence levels of 50% and 98% for 34 meteorological stations in the 31 provinces of Iran, a long-term overview of the temperature situation and the required functional classification of bitumen based on the meteorological information of each station is also provided. The increase in the average temperature of the studied stations at the end of the 21-year period was 0.73 and 1.094 degrees of centigrade at a confidence level of 50% and 98%, respectively. According to these results, most of the studied areas will experience a significant temperature increase in the coming years, and this phenomenon will increase the high and low temperatures of bitumen performance, which will require the use of PG76-10 and PG82-10 bitumen. The increase in high and low performance temperatures will require the use of alternative bitumens and the use of appropriate bitumen additives for all climatic conditions.