In this present study, the effects of Ethylene-Vinyl-Acetate (EVA) on the conventional characteristics and rheological properties of pure bitumen were investigated. The modified bitumen (PMB) has been prepared in laboratory by mixing bitumen with copolymer EVA. Three different contents of polymer have been tested to evaluate the modification. The basic properties of the PMBs have been determined by using conventional test methods. The results indicated that polymer modification improved the conventional properties of the base bitumen such as; penetrability, softening point and temperature susceptibility. Some observations by UV florescence microscopy have been performed to show the differences in the morphology of the PMBs as a function of polymer content. The rheological behaviour was evaluated with a widely used test that is the complex modulus test in order to reach a model. The results of the investigation indicate that the rheological models can reproduce the effect of polymer modifications with an increase of initial modulus and a decrease of the relaxation time and phase angle with polymer content. Two rheological models such as Huet modified model and Prony series model were used to to characterize the rheological behaviour
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