Optimal Application Timing and Cost Effectiveness of Crack Sealing in Asphalt Concrete Overlays in Louisiana

Crack sealing in asphalt concrete (AC) overlays is an important component of pavement preventive maintenance. The objectives of this study were to evaluate the cost-effectiveness of crack sealing applied on AC overlays (flexible and composite) in Louisiana considering the pre-treatment overlay conditions and to determine the optimal timing of crack sealing. To achieve these objectives, AC overlay, crack sealing, and chip seal projects in Louisiana were identified for data collection. Based on the data collected, the equivalent annual cost (EAC), life-cycle cost analysis (LCCA), and cost-effectiveness (CE) approaches were employed to identify the optimal timing of crack sealing. Additionally, a case study was considered including five different alternative strategies for which the LCCA was calculated to identify the optimal long-term strategy as well as the corresponding optimal timing of this strategy. The results of the cost-benefit analyses for the field projects and case study were compiled and analysed to provide the final recommendation for crack sealing. Results indicated that the cost-effectiveness of crack sealing is optimum when the pre-treatment overlay condition ranges between 81 and 89. When the pre-treatment overlay condition exceeds 90, crack sealing should not be applied. Based on the results of this study, a series of automated excel spreadsheets were developed to allow the user to predict the cost-effectiveness and optimal timing of crack sealing knowing the project conditions and costs without the need for additional calculations.