laboratory evaluation of the fracture resistance of asphalt mixtures containing carbon fibers

The most common distresses of asphalt pavements are fatigue and cracking, which can lead to stripping and structural failure. the fracture mechanic concepts can be used to evaluate pavement material’s resistance to crack initiation and propagation. the cracking behavior of asphalt mixtures can be improved by fiber reinforcement. the addition of carbon fibers can strengthen asphalt binders or mixtures. the optimum length and content of carbon fibers in asphalt binders and mixtures need to be investigated to improve their cracking behavior. in this paper, carbon fibers with different contents and lengths were added to asphalt binders and mixtures, and their fracture, fatigue, resilient modulus, tensile strength, and flexural bending strength were investigated. the results showed that adding up to 1.5% of fibers leads to an increase in the fracture and fatigue performance of the mixtures. the mixtures containing fibers with lengths between 15 mm to 20 mm indicated the best performance in terms of fatigue, fracture, and tensile strength. the results of the mixed-mode scb fracture and the rscb tests of the mixtures reinforced with the optimum fiber length and content show that the highest fatigue and fracture resistance happens in the pure mode ii condition. the effective fracture toughness and fatigue life decline by approaching the mode i condition asphalt binder test results showed that fiber reinforcement was significantly effective in improving the flexural strength of the asphalt binders and mastics.