Studying the Effect of Adding Carbon Fiber on the Fatigue Failure of Asphalt Mixture

In contrast to other configurations used in civil engineering, asphalt concrete (AC), which is a blend of bitumen and aggregates, is a sensitive substance. Consequently, efforts are made continuously by scientists and engineers to enhance the functionality of asphalt pavements. One strategy to enhance pavement performance is to modify the asphalt binder. Various materials have been used to strengthen asphalt concrete in modern times. Moreover, fibers are significant examples that are employed in this way. Nonetheless, it has been asserted that fibers have drawn the most attention among different asphalt modifiers due to their enhancing properties. Various studies have reported on the outcomes of adding a wide range of fibers to asphalt concrete. Therefore, the purpose of this study is to investigate how Hot Mix Asphalt (HMA) concrete behaves in the presence of certain carbon fibers (CF) in the asphalt mixture. This study examines the impact of incorporating carbon fibers into asphalt mixes through an experimental investigation. The current project uses asphalt with a grade of 40‒50 and aggregate percentages that meet Iraqi requirements. The creation of mixes with varying asphalt doses (4‒6.5%) yields the ideal asphalt content of the asphalt concrete mixtures. To produce specimens, the ideal bitumen concentration of 4.9% was employed. The ratio of carbon fibers to mixture volume (1.5%) is used to examine the effectiveness of paving mixes. The performance of HMA mixes was found to be enhanced by the inclusion of carbon fibers in terms of the HMA’s ability to withstand fatigue crack. CF acts as a reinforcement material, providing additional strength and stiffness to the asphalt binder-aggregate matrix, thereby delaying the onset of fatigue damage. CF reinforcement can lead to a significant increase in the fatigue life of asphalt mixtures. There was a 16% increase in stiffness, reducing the cracks under cyclic loading CF can delay the initiation of cracks in asphalt mixtures subjected to repeated bending loads. Fibers in the mixtures increasing amount of strain energy absorbed through fracture and fatigue activity, the number of cycles (Nf) greatly increased with additions 1.5% CF and improved by 46%.