A number of highway agencies have designed and constructed jointed plain concrete pavements (JPCP) with unsealed joints for many years. However, the performance of such JPCP and their performance relative to those with sealed joints is not well documented. Without this information, a rational selection of sealed or unsealed JPCP cannot be made. The data available from the Long Term Pavement Performance (LTPP) studies are expected to provide information relevant to this issue.

Research was conducted to compare the performance of JPCP with unsealed joints to those with sealed joints.

The objective of this research was to compare, based on the data available from the LTPP studies, the performance (as measured by distress) of JPCP designed and constructed with unsealed joints with that of JPCP with sealed joints. The research was limited to using the data available in the LTPP Information Management System (IMS) database classified as "Level E."

Accomplishing this objective involved the following tasks: (1) Collect and review reports relative to the LTPP studies on the performance of JPCP with unsealed joints to obtain the information needed to accomplish the project objectives. From the data elements available in the LTPP database, identify the elements needed to conduct this research and determine the extent of availability for each. Acquire the needed data and develop a database that includes the data proposed for use in the project. (2) Based on the information obtained in Task 1, develop a data analysis plan for determining the relative performance of JPCP with sealed and unsealed joints. The analysis plan shall consider the performance of pavement sections included in the Specific Pavement Studies (SPS) and the General Pavement Studies (GPS) experiments. While the SPS experiment on maintenance of rigid pavements (SPS-4) will provide direct comparisons of performance, the experiment on JPCP (GPS-3) may provide information on the performance of JPCP with unsealed joints. (3) Within 4 months, submit for NCHRP review and approval a progress report that documents the research performed in Tasks 1 and 2 and includes the details of the work plan for Tasks 4 and 5 of the project. Work on Task 5 proceeded while the report was being reviewed, and the work plan for Tasks 4 and 5 was revised in accordance with the review comments. (4) Execute the plan approved in Task 3. (5) Submit a final report that documents the entire research effort.

The final report was published as NCHRP Web Document 32.