Monitoring of cracks has become a major challenge to maintenance and management agencies of pavement. Research on crack monitoring has also been massively carried out, nevertheless, mostly in describing the features and evaluating the severity of existing cracks in pavement. Mechanisms of crack initiation and estimation of the emerging time of crack has induced research interest among industry insiders. The degradation of pavement structure to cracks (major and minor) is a gradual process, therefore continuous monitoring of the internal damage state is necessary to predict the crack initiation. This can be done by utilizing a wireless sensor system embedded in pavement structures. In this paper, comprehensive research on the detection of surface cracks and the monitoring of the crack initiation are reviewed respectively. There is a suggestion at the end of this paper that the final solution to the real-time continuous monitoring of the cracks in asphalt pavement is the smart pavement constructed with smart materials.

Keywords: Crack monitoring, Asphalt pavements, Crack propagation, Sensors, Crack detection