Fatigue performance and thickness optimization of polyolefin fiber-reinforced M40 concrete for sustainable pavements

Concrete pavements are renowned for their ability to handle heavier loads and lower life cycle costs than flexible pavements. Fibers into concrete further enhance its durability by reducing maintenance and rehabilitation costs. This study investigates the fatigue performance of pavement quality concrete (PQC) M40-grade reinforced with polyolefin fibers, focusing on structured fibers (SF) and twisted fibers (TF). Polyolefin fibers were added at varying dosages (0.8, 0.9, and 1.0 kg/m³ for structured fibers and 3, 4, and 5 kg/m³ for twisted fibers), as per IRC: 44 (2017) guidelines. Tests were conducted for compressive, split tensile, flexural strength, and flexural fatigue under different stress levels and loading frequencies. Results revealed that polyolefin fibers significantly improve concrete’s mechanical properties and fatigue resistance. Optimal dosages were identified as 1 kg/m³ for structured fibers and 5 kg/m³ for twisted fibers. The S-N curves demonstrated enhanced durability under cyclic loading conditions. Furthermore, polyolefin fiber reinforcement reduced white topping thickness from 19 cm to 17 cm while maintaining flexural stress within safe limits. This optimization highlights the potential for more durable, cost-effective, and sustainable pavement solutions.