Abstract Manager

The use of fibres in asphalt concrete mixes has become popular for many applications including inhibiting premature distresses in asphalt pavements, enhancing fatigue and rutting resistance, and lowering life cycle costs. Specific to cold temperatures and increasing vehicular loads, thermal failure is a widespread phenomenon that manifests as a series of transverse cracks extending across the pavement surface. Hence, using high-strength fibres (such as steel fibres, elastomeric polymers, etc) to increase tensile strength has become a viable solution. The traditional approach for determining the optimum dosage of any type of fibre for use in asphalt mixes includes trial and error, previous testing literature or tapping into existing agency knowledge and best practice. This study adopts a framework for determining optimum fibre content that employs asphalt volumetrics and performance tests. This framework is represented in an accept-reject criteria-based flow chart to reach the optimum fibre content for use in high performance asphalt concrete (HPAC) applications in cold regions such as Canada. In this study, we add different percentages of one length of polyethylene terephthalate (PET) to prepare samples with asphaltenes-modified binders for use as a base course in cold climates. In order to determine which PET percentage gives the optimum result, different criteria are analyzed, including compactibility, dynamic modulus, as well as creep compliance and indirect tensile strength. In this work, the criteria for a sample’s compactibility was considered as a maximum 6% of air voids for the compacted speciments using 80 gyrations by a Superpave gyratory compactor. In addition, considering that this study aims to enhance HPAC for cold climate applications, dynamic modulus of HPAC mixes should be greater than 14 GPa at a temperature of 15˚C and a loading frequency of 10 Hz. Finally, to increase the pavement's lifespan, the mixtures with optimum dosage must be prone to minimum thermal cracking at low temperatures by exhibiting the highest creep compliance and fracture energy compared with the control samples. This framework can be adjusted to add or omit other performance tests that are most suitable for the project location and climate in question.