Review of reflective cracking mechanisms and mitigations for airport pavements

Many Australian airport pavement systems include old plain jointed concrete pavements near the end of their service life. Rehabilitation by asphalt overlay is often an attractive and costeffective option but introduces the risk of reflection cracking. In this context, reflection cracking is the propagation of cracks in the asphalt layer triggered by relative movement across the joints, either as a result of traffic loading or thermal variations. A review of reflection cracking mitigation options indicates that bituminous or geosynthetic interlayers and increased asphalt thickness are the most common strategies, with combination treatments considered the most likely to significantly reduce reflection cracking risk. Although the mechanisms and causes of reflection cracking in airport pavements are generally understood, further work is required to better understand the relative benefit of the various mitigation treatments. It is recommended that further research be undertaken to develop a method for the objective comparison of various mitigation options, through a combination of laboratory testing and numerical modelling, calibrated to field-performance observations