Evaluation of Intermediate and High Temperature Behavior of Binder Modified by Ethylene Vinyl Acetate-Montmorillonite Nanocomposite

Asphalt pavements are one of the most widely constituents utilized to pave highway pavement which experience various failures during their lifetime, such as rutting, fatigue and thermal cracking. Therefore it should be used to improve the bitumen performance by addition of modifiers such as polymers and NanoClays (NC). Among the various additives used to improve the bitumen performance, Ethylene Vinyl Acetate (EVA) is one of the most useful and effective materials for paving. In this study, the rheological behavior of bitumen and fatigue behavior of mixture containing EVA/Nanoclay and EVA latex were evaluated. In order to evaluate the intermediate and high temperature behavior of binder, the Linear Amplitude Sweep (LAS) test and Multiple Stress Creep Recovery (MSCR) test were implemented. EVA/NC and EVA latex were made and mixed with bitumen. Results of storage stability test shown that EVA/NC-modified bitumen is steadier than EVA-latex-modified bitumen. MSCR test results indicated that addition of EVA/NC and EVA latex to original binder led to decrease and decrease the percent recovery and non-recoverable compliance (Jnr) values, respectively. Also LAS test results show that addition of EVA/NC and EVA latex to original binder cause an enhance in fatigue behavior of binder. According to climatic regions in Iran and required PG binders, it can be concluded that binder modified with 4% EVA/NC can use in all climatic zones in Iran followed by 6% EVA/NC modified binder.