Effect of Various Fibers and Filler Materials on the Mechanical Performance of Stone Matrix Asphalt Mixtures

The frequent need for repairs and maintenance in conventional hot mix asphalt, caused by premature failures under heavy traffic loads, has led to increased consumption of natural aggregates and bitumen. This study explores stone matrix asphalt (SMA) technology as a solution, known for its superior rut resistance and extended service life. A key innovation of the study lies in the incorporation of various waste and natural fibers, namely, natural cellulose, jute, banana fiber, and cellulose pellets combined with two different filler materials: crusher dust and hydrated lime. These materials were selected to reduce reliance on synthetic components and to repurpose waste fibers, with the objective of checking their suitability as alternatives to synthetic fibers. To assess the impact of these materials, a range of performance tests, including binder draindown, resilient modulus, tensile strength ratio, ideal rutting tolerance, and ideal cracking tolerance tests, were conducted. Although the results showed that hydrated lime (HL) improved most performance parameters (up to 60%), it negatively affected cracking resistance (decrease up to 54%). Further, natural fibers, particularly jute and banana, enhanced the mixtures’ resilient modulus, indirect tensile strength, and rutting performance up to 27%–66%. Significant improvements in cracking resistance were observed with the use of pelletized cellulose fibers, showing up to 66% enhancement compared to other fiber types. The incorporation of these fibers not only improves the mechanical properties of the SMA mix but also contributes to reusing the waste fibers. This study underscores the potential of SMA technology to extend pavement lifespan, reduce repair frequency, and promote waste derived construction practices. The findings present a promising approach in asphalt construction by improving the durability and life span of asphalt mixtures by use of natural fibers.