Sawing and Sealing Joints in Bituminous Pavements to Control Cracking

Summary

Sawing and sealing (S&S) is a preventive crack-control strategy used by Minnesota local agencies to manage transverse cracking and improve maintenance predictability. This project provides MnDOT and local agencies with updated information on the use of this strategy and compares two existing crack-control approaches: a lower-cost Binder B strategy combined with S&S versus a higher-cost Binder C strategy without S&S. This work synthesizes published practices and experience in Minnesota, compiles and interprets available Minnesota performance information, and examines how subgrade condition and environmental risk factors affect expected S&S performance. A mechanistic-probabilistic framework is used to investigate thermal shrinkage and relate material variability, mixture tensile strength, and joint spacing to crack spacing and cracking risk, supporting reliability-based evaluation of joint spacing and timing of crack treatment. Life-cycle cost analysis comparisons are performed using existing assumptions for treatment schedules and costs over representative analysis periods and traffic levels. Two practical screening and monitoring methods, which leverage Road Doctor survey-van condition indicators and Nira Dynamics in-vehicle roughness data, can be used to monitor ride quality over time and detect seasonal and long-term roughness changes for maintenance planning and performance tracking.