Evaluation of Asphalt Overlay Pretreatments against Reflective Crack Using Association Rule Mining

Reflective cracking has been a concern for the performance of asphalt overlay on existing concrete pavements. Due to daily temperature fluctuation and traffic loads, significant movements of slab joints or cracks drag the overlay to produce critical stresses. Afterward, cracks initiate in the overlay and propagate toward the surface. The occurrence of this distress can compromise the benefit of the overlay earlier than the design expectation. Accordingly, mitigation of reflective cracking is typically considered during the rehabilitation selection process. Overlay pretreatment, such as rubblization, crack and seat, or an interlayer system, is one of the mitigation methods that is typically implemented prior to the overlay placement. Each approach is beneficial to the overlay performance in delaying or eliminating early reflective cracking. However, they may generate different efficiency levels in overcoming crack growth. Therefore, this study intends to conduct two analyses on the in situ performance of pretreatments using the long-term pavement performance program (LTPP) database. Initially, the study carries out the statistical comparison of pretreatment quality against reflective cracking. Sequentially, the association rule mining method is utilized to discover the potential correlation of design elements in the data set that influence reflective crack development. The study demonstrates that crack and seat and rubblization effectively mitigate premature reflective cracking in asphalt overlay. Moreover, the association rule mining method simplifies the massive data set into comprehensible relationships that are favorable to overlay design decision-making. Further, application of thick overlay or pretreatments can noticeably postpone the chance of severe reflective cracking up to 67% and 45%, respectively.