Evaluation of Strength and Water Susceptibility Performance of Polypropylene Fiber-Reinforced and Silica Fume-Modified Hot Mix Asphalt

The use of industrial recycled waste material has exponentially increased in past decades for green and sustainable construction practices. Numerous industrial wastes are being effectively used to replace the conventional construction material with paved structure construction. The use of industrial waste ash to replace the mineral filler and plastic waste as reinforcement has shown tremendous scope for use in hot mix asphalt (HMA). This research aims to explore the effect of alternative mineral filler and fiber reinforcement in HMA. In the present study, an extremely fine nanocrystalline polymorph of silica fume (SF) and polypropylene (PP) fiber was used as mineral filler and reinforcement. The varying percentages of SF (i.e., 4.0 %, 6.0 %, and 8.0 %) and PP fiber (0.25 %, 0.5 %, 0.75 %, and 1.0 %) by volume of total mix were used. The strength and durability of the HMA were evaluated using Marshall Stability, indirect tensile strength, mean Marshall Stability ratio, index of retained strength, water sensitivity, indirect tensile fatigue test, and rut depth tests. The statistical significance analysis has been carried out using the analysis of covariance. The loss of indirect tensile strength was observed between 16-18 % at the optimum limits of the SF and PP fiber; this signifies the higher durability of PP-fiber-reinforced HMA modified with SF. Ministry of Road Transport & Highways (MoRTH), 2013. The results also show the use of PP fiber and SF significantly improves the strength and durability of HMA.