عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Growth of traffic factors such as high traffic volume, travel of heavier vehicles with more tire pressure, demand higher-strength asphalt mixes. Researches in recent decades have shown that using polymers and fibers in asphalt mixes has delayed failures and improved properties of the asphalt pavements. In this research, effects of ethylene vinyl acetate (EVA) polymer on the fatigue behavior of bitumen and asphalt mixtures are investigated and analyzed. So, linear amplitude sweep (LAS) tests and elastic recovery of bitumen are used to characterize fatigue behavior of bitumen and the four-point bending beam test is used to measure fatigue life of asphalt mixtures. Elastic recovery results showed that modifying bitumen with EVA enhanced elastic and recovery properties of the bitumen. The LAS test data showed that modified bitumen has better resistance against high strain and slows down the growth of failure trend. The results of LAS test showed that EVA-modified bitumen improves the viscoelastic properties, performance and fatigue behavior of the bitumen. Also, comparison of the results of this test at 20 and 30 °C showed that pure and modified bitumen have higher fatigue life and better fatigue resistance at 30 °C. By increasing the temperature, bitumen becomes softer, its viscoelastic behavior is revealed better, and recovery of thin cracks, caused by loadings, is faster. Also, results of beam fatigue test showed that the modified mixes with this polymer have higher fatigue life, compared to pure bitumen specimen.