The Impact of Polyethylene Terephthalate (PET) Fibres on the Cracking Resistance of High-Performance Asphalt Concrete (HPAC)

ABSTRACT
The safety of a road network highly influences its overall productivity and efficiency. High-performance asphalt concrete (HPAC) is an innovative paving mixture in the design and construction of high-traffic roads in North America, which has high strength, good fatigue life, and excellent rutting resistance. However, the HPAC application is limited in colder regions because of the material's low flexibility and stress relaxation capacity. A road pavement undergoes different types of defects and failures throughout its design life, and cracking is one of them. Cracking in the asphalt pavement is introduced by numerous causes, such as heavy traffic, low temperature, and poor drainage. Cracking in the asphalt pavement negatively affects a road's lifespan and increases the maintenance cost of a road. Therefore, the objectives of this study are to evaluate the impact of asphalt mix modification in terms of resistance to cracking and improvement of cracking tolerance in high-performance asphalt concrete with the utilization of Polyethylene Terephthalate (PET) fibres in the mixes. Three different lengths of PET fibres (6 mm, 12 mm, and 18 mm) are used in the mixes. A binder source-H with PG 70-22 is used for fabricating the HPAC throughout this research, which is modified with 12% asphaltenes (by the weight of binder). An indirect tensile cracking test (IDEAL-CT) at an intermediate temperature of 25C and at 37C according to the PG grading of the binder as per ASTM D8225 for all the asphalt mixes is carried out to determine the cracking tolerance (CT) index values, failure energy, and indirect tensile strength. The analysis of the test results shows that the failure energy and the indirect tensile strength properties of the asphalt mixes are improved with the addition of PET fibres in comparison with the control mixes at 25C. However, it is observed that increasing the fibre length improves the CTIndex, failure energy, and indirect tensile strength when the specimens are tested at the temperature of 37C.