Evaluation of asphalt binder and mixture properties utilizing fish scale powder as a biomodifier

Abstract

Fish represents an abundant and underutilized waste product from the fishing industry. This study investigated the effects of incorporating fish scale powder (FSP) at various dosages (3%, 6%, 9%, and 12%) on the properties of asphalt binder and mixtures. Conventional tests, viscosity, storage stability, Fourier transform infrared spectroscopy, and multiple stress creep recovery tests were conducted on the binder. Mix design, wheel tracking, indirect tensile strength, fatigue, and ultrasonic pulse velocity tests were evaluated for the asphalt mixtures. The results showed that FSP increased the binder’s stiffness and reduced the temperature susceptibility but compromised the low-temperature performance and workability regardless of the dosages. The storage stability test results demonstrated the improved high-temperature storage stability. In the mixtures, the permanent deformation resistance enhanced with increasing the FSP content, decreasing the rut depth from 4.3 mm for the control sample to 2.9 mm at 12% FSP. The moisture damage resistance, indicated by the tensile strength ratio, increased from 90% for the control sample to 94.1% at 12% FSP. However, the fatigue life decreased from 14010 cycles for the control sample to 11190 cycles at 12% FSP. The dynamic and elastic modulus values before conditioning increased with higher FSP dosages, and this increasing trend was also observed after conditioning, signifying greater stiffness retention and moisture resistance of the asphalt mixtures containing higher amounts of FSP. Numerically, the 6–9% FSP range offered the optimum balance, improving the rutting resistance by 18% and the moisture resistance by 3.2% compared to those of the control sample, while limiting the fatigue life to 12% and maintaining the workability. Overall, FSP has potential for use as an asphalt biomodifier by transforming an environmental liability into a value-added sustainable paving material.