Verifying laboratory measurement of the performance of hot asphalt mastics containing plastic waste

As a response to the “end of waste” strategy, this study focuses on an innovative laboratory-methodological approach to carrying out measurements for multi-scale characterization of road pavements construction materials; specifically, the engineering performance of sustainable hot asphalt mastics made up using plastic waste as filler was measured to gain a deeper understanding of the physico-machanical performance of traditional and modern mastics, which seriouly affect the design and durability of the final whole road asphalt pavement. Asphalt mastics are bitumen-based materials that give cohesion to the whole asphalt mixture. They consist of filler (with a passing by mass percentage ranging from 70 to 100 for a sieve size of 0.063 mm) and bitumen. Nine asphalt solutions prepared using three percentages of filler content (10, 15, and 20%) by the total weight of neat bitumen whose weight was kept constant were investigated. Firstly, for plastic waste particles, the maximum melting temperature was examined using Differential Scanning Calorimetry, and the phase transitions were subjected to thermogravimetric analysis. The morphology of all the asphalt solutions was then observed using Scanning Electron Microscope, while the advanced rheological properties were measured by means of a Dynamic Shear Rheometer. Cluster Analysis and Principal Component Analysis were performed to aggregate solutions with similar performance within the same group, and, secondly, to provide a small number of uncorrelated explanatory laboratory variables. Three clusters and three Principle Components were found to be perfectly interconnected to describe asphalt mastics performance.