A Review of Fatigue Cracking in Asphalt Mixtures: Mechanism, Influencing Factors, Testing, and Mitigation Methods

Effectively preventing early failure and assessing the impact of new materials and technologies on cracking performance depend on a thorough understanding of the mechanics behind pavement cracking. One of the most common distresses on asphalt pavements is fatigue cracking. Tensile stress owing to repetitive traffic loads produces increasing damage every day. Two types of fatigue fractures happen in asphalt pavement. Top-down cracks lead to penetrating water and dust; therefore, potholes will occur, leading to an uneven pavement surface and rider discomfort. Bottom-up fatigue cracks lead to pavement structure degradation. This paper presents a review of fatigue crack propagation mechanisms, the elements that affect and hasten their development, and evaluation by small-scale laboratory and large-scale on-site experiments. A literary review of prior experiments that involved the use of asphalt modifiers, fibers, and geosynthetics for the objective of strengthening asphalt mixes to minimize or restrict the formation of fatigue fractures and lengthen the lifespan of the asphalt pavement. It found that fatigue cracks are unavoidable owing to the exposure of asphalt pavement to repetitive loads and harsh ambient environmental conditions. Laboratory tests done on asphalt mixes are used solely to compare asphalt mixtures with one another because there are no specific or critical values for test results approved by American and European norms. However, considering the astounding pace at which technology is evolving, this may have a promising future.