Mechanical performance of asphalt mixtures using polymer-micronized PET-modified binder

The global engineering plastics market has been growing as it replaces materials such as glass and metal. It can be used in a wide variety of products and technologies in other sectors of the economy such as energy generation, automotive, maritime, construction, electronics, packaging, and others. However, this increase in global use presented problems with respect to the increase in plastic waste generation. The existence and destination of plastic waste in the soil and hydric resources has been recognised as an emerging issue in preserving the environment. In this research, Micronized Polyethylene Terephthalate (micronized PET) was used as an additive for asphalt mixtures. The polymer was mixed in amounts of 4%, 5%, and 6% by weight with an asphalt binder base and mechanical tests were performed. Two SUPERPAVE mix design methods were performed. The first one was made with pure binder and the optimum binder content was determined and the specimens were analysed according to the following parameters: Resilient Modulus (RM), Lottman, and Indirect Tensile Strength (ITS). A second mix design procedure was performed with the optimum PET content according to the best results obtained in the first one, and analysed according RM, ITS, Lottman, Fatigue, and Flow Number tests. The results show significant improvements on mechanical properties of the asphalt mixtures with micronized PET compared with asphalt mixtures without additive.