Holding Strategies for Low Volume State Routes - Phase II

The objective of the proposed research project is to assist Iowa Department of Transportation (Iowa DOT) in developing strategies for maintaining lower volume highways that are near the end of their service life to a satisfactory level in order to delay the larger expense of rehabilitating or reconstructing them. A technical advisory committee (TAC) will be established to assist Iowa State University in its efforts to execute this research project including representation from the Iowa DOT, local agencies (county and/or city) and industry. The tasks for this proposal are outlined below. The level of effort for each task will be determined in consultation with the chair and other members of the TAC. The total effort will remain within the scope of the budget unless authorized in advance by the Iowa DOT. The intention is to provide flexibility to meet unforeseen challenges and to take advantage of unexpected opportunities. Researchers will collaborate with the TAC and designated Iowa DOT personnel to design and execute a holding strategy construction project for an Iowa roadway. Within this construction project, a series of test sections and a control section will be placed. The plan for the test sections will be developed to be appropriate for the local condition for the roadway and the construction budget that the Iowa DOT has available to accomplish the project. A combination of Iowa State University and Iowa DOT resources will be used to accomplish the objective. This scope of work provides for two sets of test section post-construction observations after construction is complete. Since experimentation with holding strategies is expected to be an ongoing effort, it is assumed that further post-construction observations may be funded as part of subsequent research projects. Monitoring of the Iowa 93 test section will also continue in this phase of the project. (Task 1) Literature Review and interviews. The research team will conduct a complete review of published literature including academic journals, international journals, trade publications, product literature and Internet web pages. It is expected that the search will initially identify many articles on preventive maintenance and pavement preservation which may be somewhat related to this topic, but are not on target. Since the research team has considerable experience on those other topics, it will be possible to quickly remove those from consideration and focus on literature involving holding strategies. The literature review for this phase of the research will build on previous literature reviews that were conducted for the first phase of the project. This will reduce the effort required for this task making additional effort available for other tasks. (Task 2) Pre-design Investigation. A pre-design investigation will be conducted to ensure that the test sections for holding strategies are appropriate for the local circumstances. The investigation will commence by interviewing district maintenance personnel and reviewing maintenance and construction records for the selected roadway. In addition, current information from the Mile Post Test Section Book will be reviewed and output from the biannual pavement management data collection effort will be reviewed. Included in the biannual data collection is the IRI (international roughness index) for each wheel path, longitudinal and transverse cracking, alligator cracking, and rutting. 'FWD (falling weight deflectometer) data is collected on a six year rotation. After this review has been accomplished, an additional effort will be launched to provide information that was not available from the previous sources, if necessary. That additional effort might include: Cores to assess current pavement and base section characteristics; Geo-technical characterization of the sub-grade such as using the dynamic cone penetrometer; and FWD testing if FWD tests have not been conducted within the last two years. All of the above will, if needed, be provided by the Iowa DOT. The results of this testing program will be reviewed, and feasible holding strategy concepts will be selected for possible inclusion in the test sections. (Task 3) Test Section Design. An experimental design to compare holding strategies will be developed to fit within the Iowa DOT budget and the circumstances documented in the predesign investigation. Constructability of the test sections will also be considered. It is expected that four to six test sections plus a control section will be designed. The design for the control section will reflect the current treatment that the Iowa DOT would typically use for a road that exhibits similar preconstruction conditions to that of the roadway selected for this project. It is expected that the test sections will be a combination of seal coats, cold in-place recycling, hot in place recycling, inter layers and other applications such as surface treatments and HMA overlays as appropriate. After the design is developed, the Iowa DOT will create contract documents and procure construction services through the Iowa DOT letting process. (Task 4) Test Section Construction. The test section construction will be executed in accordance with the contract documents developed in Task 3. Researchers will update the preconstruction surface distress survey immediately before construction and observe critical processes of construction to the extent possible within the budget and provide technical support. The Iowa DOT will provide its usual construction management services. (Task 5) Post Construction Monitoring. Post construction monitoring efforts will include: Photographs, a surface distress survey, roughness measurements, coring to assess the condition of recycled layers, and FWD testing. These efforts will be arranged to focus on documenting critical changes in performance and will continue for one season after construction is accomplished. Continued monitoring of the Iowa 93 test sections will continue in this task too. (Task 6) Data Synthesis. The research team will review the documentation that was generated from previous tasks and develop an initial assessment of the success of each strategy. The assessment process will include practical concerns such as ease of material selection, design and specification development, constructability, cost and schedule. Longer term assessments could be provided with subsequent phases of this research project. (Task 7) In-house and Contracted Effort. Based on knowledge obtained in the previous tasks, especially Task 1 - Literature Review and Interviews, an analysis will be conducted. This analysis will be included in the final report. (Task 8) Final Report. A final report will be developed that describes the investigation and provides conclusions and recommendations, based on the observations that have been conducted up to the time of writing.


    • English


    • Status: Active
    • Funding: $100642
    • Contract Numbers:


      Add 634

      ISU Proposal Number 140390

    • Sponsor Organizations:

      Iowa Department of Transportation

      800 Lincoln Way
      Ames, IA  United States  50010
    • Managing Organizations:

      Iowa State University, Ames

      Center for Transportation Research and Education
      2711 South Loop Drive, Suite 4700
      Ames, IA  United States  50010-8664
    • Project Managers:

      Todey, Francis

    • Performing Organizations:

      Iowa State University, Ames

      Center for Transportation Research and Education
      2711 South Loop Drive, Suite 4700
      Ames, IA  United States  50010-8664
    • Principal Investigators:

      Williams, Chris

    • Start Date: 20171101
    • Expected Completion Date: 20190731
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01651531
    • Record Type: Research project
    • Source Agency: Iowa Department of Transportation
    • Contract Numbers: TR-735, Add 634, ISU Proposal Number 140390
    • Files: RIP, STATEDOT
    • Created Date: Nov 27 2017 10:51AM