Performance Evaluation of Concrete Pavement Restoration Treatments
I. RESEARCH PROBLEM STATEMENT
New concrete pavements are now being designed by highway agencies for long life with initial service life expectations of at least 40 years. It is expected that for new concrete pavements, there will be very little need for pavement restoration activities during the as-designed pavement service life. However, there are thousands of miles of existing concrete pavements that were constructed over 20 years ago, and designed for a service life of 20 to 25 years, that are exhibiting various levels of distress. These pavements, many with actual service lives exceeding 40 years, need to be restored economically and in a timely manner to continue to provide and maintain an expected level of service without resorting to fracturing of the existing concrete pavements or to reconstruction, both of which are more capital-intensive alternatives.
Over the years, several concrete pavement restoration (CPR) techniques have been developed and refined. Many of the CPR techniques are widely used by highway agencies on a routine basis to restore the condition of existing concrete pavements. These techniques include partial-depth repairs, full-depth repairs including use of precast panels, dowel bar retrofit, diamond grinding, edge drain retrofit, cross stitching, slab undersealing, slabjacking, and concrete or roller compacted shoulder retrofit. Many of these techniques are performed under accelerated schedules. However, there is not much data on the long-term performance of these CPR techniques. Although agency and industry guidelines and specifications exist for these restoration techniques, no definitive globally validated data has been documented regarding the long-term performance of these techniques with respect to regional practices, climatic effects, repair materials, speed of construction, and traffic volumes. Limited agency-specific and repair technique-specific studies have been conducted, but overall, much of the performance-related information is based on anecdotal information or is based on a limited period of observation. As such, there is a critical need to determine if the CPR techniques, as currently practiced, are in fact meeting the needs of long-term repair solutions and if refinements in design and construction details are needed for some or all of these techniques. In addition, there is a critical need to review agency practices and develop harmonized project selection, design guidance, and construction specifications for these CPR techniques.
There is a significant amount of literature related to guidance on CPR techniques. Also, most agencies have developed CPR construction specifications. However, there is little reported or widely distributed information on CPR performance over a extended periods of time. Typically, performance information is only reported for 3 to 5 years after construction. In addition, there has not been a significant effort expended to review experiences from one agency to another and to learn from the successes and failures of innovations in these techniques.
The objective of this project is to evaluate the performance of CPR techniques, including those performed under an accelerated schedule, across multiple agencies, and to incorporate improvements in these techniques based on long-term field performance. The field evaluation will include condition survey of the repair sites and deflection testing, as applicable, to assess the pavement structural capacity at the repair sites.
III. RESEARCH PROPOSED
The following tasks have been identified to complete the work for this project:
Task 1. Conduct a literature search and survey of US and Canadian transportation agencies on CPR techniques and information related to long-term performance.
Task 2. Identify CPR techniques and potential test section locations for further evaluation.
Task 3. Develop and conduct a field evaluation plan to access the current condition of the CPR techniques, obtain agency performance data, and discuss current agency thoughts on CPR applicability and long-term performance.
Task 4. Analyze field condition data, associated long-term performance information, cross agency techniques, and lessons learned.
Task 5. Propose revisions to CPR project selection criteria, design guides, and construction specifications based on the information gained from task 1 through 4.
IV. ESTIMATE OF PROBLEM FUNDING AND RESEARCH PERIOD
The estimated funding for the project is $400,000. The estimated time to conduct research is 30 months.
V. URGENCY, PAYOFF POTENTIAL AND IMPLEMENTATION
There is a critical need for this project to ensure that CPR, especially under accelerated schedule is performed effectively and results in long-lasting services lives. On urban and other high volume roadways, we can no longer afford to use CPR treatments that have been used in the past, but may not be providing the long-term extension of the pavement service life. Implementation of findings from this project will help refine existing CPR treatments and provide an impetus to develop improved design and construction practices that will lead to longer service lives. This will reduce/eliminate the “fix the fix” problem. Implementation of findings from this project will benefit the users (less congestion and safer travel due to less frequent lane closures), reduce vehicle operating costs, and importantly result in less maintenance expenditures by highway agencies. Implementation timing can be immediate upon completion of the project. An important aspect of this study will be the determination of the performance of the CPR techniques constructed under accelerated schedules.
VI. RELATED RESEARCH
VII. PERSON(S) DEVELOPING THE PROBLEM STATEMENT
VIII. PROCESS USED TO DEVELOP PROBLEM STATEMENT
IX. DATE AND SUBMITTED BY
Chair, TRB Committee on Pavement Rehabilitation
June 1, 2013