Simultaneous effects of ethyl vinyl acetate (EVA) and glass fiber on the properties of the hot mix asphalt (HMA)

One of the best ways to improve the asphalt mix performance is to increase the adhesion among its components using different additives. Considering the viscoelastic behavior of bitumen, adding the secondary additives as a complement can improve the properties of the asphalt mix. This study aimed to conduct a laboratory research study that evaluated the performance of asphalt mixtures prepared with ethyl vinyl acetate (EVA) modified bitumen containing different amounts of glass fibers. For this purpose, a total of 11 types of mixtures were made, and Marshall and resilient modulus tests were performed to investigate the effect of additives on specimens. The results showed that adding 5% EVA and 0.3% glass fiber increased the Marshall Stability by about 25 and 20%, respectively. It was also concluded that the simultaneous use of both additives increased Marshall Stability more than adding any of them separately. The highest Marshall Stability belongs to the sample containing 3% of EVA and 0.3% of glass fiber, which is equal to 1210 kg. On the other hand, the results of the resilient modulus indicated that by increasing the percentage of EVA and glass fiber separately and simultaneously at two different temperatures of 25 and 40 °C, the resilient modulus of the asphalt mix was increased. However, rising temperatures reduced the resilient modulus of asphalt mix. Based on all results, 3EF was selected as the most optimal asphalt mix.