Flexible asphalt pavement construction is an expensive investment. Nowadays, many methods are being investigated to improve the performance of asphalt mixtures. For this reason, bitumen is usually used with modified form in hot mix asphalt (HMA) in practice. The use of recycled waste materials as modifier additives on bitumen could have several economic and environmental benefits. The main aim of this research was to investigate the effect of HDPE (High density Polyethylene) based plastic waste materials on the performance of asphalt mixtures. For this purpose, HDPE based waste materials were added to the bitumen as modifier in to amount of 1%, 2%, 3%, 4%, then asphalt mixtures formed by the modified bitumen were tested for the determine their performances. The performance of specimens was firstly measured by stability, flow values. Then, susceptibility characteristics of the HMA to water damage were determined by using Indirect Tensile Test (ITT) method described in AASHTO T283 with classically compacted specimens. The results showed that, the best performance was obtained with a content 4% in terms of stability values. In addition, all specimens were showed resistance to water damage

The aim of this paper is to examine the rheological behavior of bitumen modified by three waste plastics (old window frames, blinds, and cables) which are composed of polyvinyl chloride (PVC). Thus, nine polymer-modified bitumen samples were produced by adding the PVC-based modifiers to bitumen at three different contents (2%, 4%, and 6%).The rheological properties of the pure and modified bitumens were analyzed by means of conventional and rotational viscosity (RV) tests as well as the dynamic shear rheometer (DSR) test. The DSR test was performed at three different frequencies representing three different traffic speeds on highways. Master curves of complex viscosity and complex modulus of modified bitumens were plotted using the data obtained from DSR test results. After polymer modification, it was observed that all modified binders behaved like Newtonian fluid, especially at lower angular frequencies. The results of the tests indicate that waste blind modification has a certain stiffening effect on bitumen. However, it provides a higher complex modulus and a lower phase angle at all traffic speeds. Modification using waste blinds of more than 4% caused difficult workability of the bitumen. This means that, by using plastic blind waste as a modifier with a 4% usage rate, it is possible to decrease wheel-tracking deformation, which is fundamental for the extension of pavement life.

Highway transportation is the most preferred transportation system as compared to other modes due to its high accessibility. Flexible highway pavement consists of mainly aggregate and bitumen, besides, in order to improve performance, some organic and/or inorganic additives are also utilized as additional constituents in the hot mix asphalt (HMA). By improving performance, positive characteristics can be gained to the HMA such as high strength, durability, toughness, suitable flexibility and resistance to impact. In this study, an attempt has been made to minimize deterioration due to the damage given by different aggressive environmental conditions. For that purpose, polypropylene fibers were added in varying ratios (0, 5, 7.5 and 10% by weight of binder) into the HMA, then these mixtures were maintained in the freeze-thaw cycling cabinet, CaCl2, NaCl and Na2SO4 solutions for a certain period. The results showed that stability increased continuously by mixtures with a content of up to 7.5% of polypropylene fibre, and then a drop was observed by 10% fibre reinforced mixtures. In addition, exposure to freeze-thaw cycles and Na2SO4 solution was found as the most harmless and harmful conditions, respectively among other environments in the investigation

The aim of this paper is to examine the effects of ground plastic pipe wastes on bitumen. For this purpose, three modified bitumen samples with modifier contents of 2%, 4%, and 6% along with pure bitumen were prepared and tested. To understand the effect of modifier on bitumen, conventional bitumen tests, rotational viscosity tests at 135 °C and 165 °C, dynamic shear rheometer tests at three different frequencies that represent three different traffic speeds, and bending beam rheometer (BBR) test were performed. The BBR test results showed that resistance of pure bitumen to low-temperature cracking increased by using additives up to 4%. Based on the results of this study, it can be said that waste plastic pipes can be used as modifier for the bitumen binder. The 4% additive showed the best performance.