Performance Evaluation of Various Rehabilitation and Preservation Treatments
Chapter 1. Introduction
According to the Federal Highway Administration (FHWA), pavement preservation is "a program employing a network level, long-term strategy that enhances pavement performance by using an integrated, cost-effective set of practices that extend pavement life, improve safety and meet motorist expectations." (Geiger, September 2005) The pavement preservation philosophy has seen increased adoption in State Departments of Transportation (DOTs) across the United States as a result of the successful educational and outreach programs instituted by FHWA and other pavement preservation organizations over the past decade. In some cases, the preservation mentality is still facing harsh political realities as politicians have a difficult time explaining to their constituents why a good road is having work performed on it while the bad roads remain untouched. Even within a State DOT, the preservation philosophy has met some resistance as it is difficult to change old habits of worst-first. The fact remains that the effectiveness of pavement preservation activities has not been well documented or publicized throughout the United States. Intuitively for pavement professionals the philosophy makes perfect sense, however, hard facts supporting this stance are still elusive except for anecdotal examples.
It is becoming increasingly important to transportation agencies to gain public support for low cost pavement preservation treatments applied to roads while they are still in good condition versus heavy rehabilitation or full roadway reconstruction which are applied to roads in poor condition. Recognizing that there is an imperative need to demonstrate the value of cost effective pavement preservation and rehabilitation treatments, the FHWA undertook this study to provide supporting documentation for preparing future guidance. This should allow agencies to demonstrate the cost effectiveness of pavement preservation strategies and perhaps begin to provide hard facts of the benefits of preservation to those who are trying to implement a pavement preservation philosophy, or those trying to promote the philosophy to politicians and senior agency officials.
The objective of this study was to conduct a synthesis to highlight the degree to which pavement preservation treatments (including minor rehabilitation treatments) extend the service life of pavements with or without adding strength. The work was carried out through an examination of current State practices and performance results in six "target" States. The study emphasizes treatments that are commonly used and known to be cost effective while extending pavement service life (preventive maintenance (PM) and minor rehabilitation) or extending both pavement service life and improving its load carrying capacity through structural enhancement (major rehabilitation). This study examined treatments for hot-mix asphalt (HMA) and portland cement concrete (PCC) pavements. Table 1 summarizes the treatments included in this study and the information solicited for each target State.
|PM and Rehabilitation Treatments||Inventory and Performance Related Data|
Hot-Mix Asphalt (HMA)
PM Treatments and Minor Rehabilitation
1. HMA overlays
10. Full depth reclamation
Portland Cement Concrete (PCC)
PM Treatments and Minor Rehabilitation
13. Diamond grinding
The report is divided into a series of chapters and appendices. Chapter 2 describes the process used to perform the data collection exercise. Chapter 3 provides a summary of the most common values for each of the treatments examined as well as a list of observations. Chapter 4 provides conclusions and recommendations related to conduct of the study and the data provided by the States.
A series of appendices are included. The conduct of the study would not have been possible without assistance from the States. Appendix A acknowledges this participation. Appendix B provides a short description of how each State that responded to this project calculates its particular pavement condition rating. Appendix C presents a series of tables that contain the data collected from the study, organized by treatment type. Appendix D contains the same information organized by climatic zone.