Field Evaluation and Cost-Effectiveness of Saw and Seal Method to Control Reflection Cracking in Composite Pavements

The Louisiana Department of Transportation and Development has tested various techniques and treatments to control reflection cracking in composite pavements since the 1970s. However, the performance and cost-effectiveness of these methods have not been consistently evaluated. The objective of this study was to evaluate the performance of hot-mix asphalt (HMA) overlays of portland cement concrete pavement sections built with the saw and seal method across the state and to assess the cost-effectiveness of this treatment method. To achieve this objective, projects with sufficient years in service and with available untreated segments were selected for detailed performance and economic evaluation. The performance of 15 different pavement sections constructed with the saw and seal method was monitored for 6 to 14 years. From the results of the analysis, it was concluded that the majority of the sites showed a positive improvement with use of the saw and seal method: 40% of the sections showed an improvement in service life from 1 to 3 years and 47% of the evaluated sections showed an improvement ranging from 4 to 12 years. The average level of improvement to the pavement service life was 4 years. The vast majority of sections (80%) indicated that the saw and seal method was cost-effective as compared with regular HMA overlays. This treatment method appeared to be more cost-effective for low to medium traffic volumes. Finite element results validated that joints constructed in the HMA overlay allowed it to move with the underlying layer and to dissipate energy generated from expansion and contraction in the concrete layer and from wheel loading without cracking.