Effects of waste wollastonite filler on hot mix asphalt performance

Asphalt pavement plays a critical role in global infrastructure, necessitating substantial annual investments for maintenance and repair. Enhancing asphalt mixture performance is essential for prolonging pavement life and reducing associated costs. This study explores the use of waste wollastonite, a neutral mineral composed of silica and lime, as a filler material in asphalt mixtures. Comprehensive micro-scale performance tests, including Marshall Stability, resistance modulus, indirect tensile strength, and moisture sensitivity, were conducted on samples incorporating waste wollastonite. The findings indicate that replacing lime filler with waste wollastonite significantly improves asphalt performance; specifically, complete substitution resulted in increases in Marshall Stability, Marshall Quotient, and resistance modulus by 30%, 28%, and 26%, respectively. Furthermore, a 70% replacement of lime with waste wollastonite led to a 9% increase in tensile strength ratio while demonstrating a notable reduction in indirect tensile strength compared to control samples. These results suggest that waste wollastonite is a viable and effective filler option for enhancing the durability of asphalt mixtures.