The objective of this research is to develop and calibrate mechanistic–empirical models that accurately predict the effects of warping on JPCP performance. Accomplishment of the project objective will require at least the following tasks. TASKS Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and subaward time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective. PHASE I—Planning Task 1. Collect and review literature relevant to factors that affect warping, including environmental conditions (e.g., relative humidity, precipitation), material behavior (e.g., drying shrinkage, creep), and pavement design characteristics (e.g., cross-section properties) and their effects on JPCP performance. The review shall include published and unpublished documentation, databases [e.g., long-term pavement performance (LTPP)], past surveys, existing models, and research conducted by or obtained from the NCHRP; the Federal Highway Administration; and other public, private, national, and international organizations. Task 2. Survey state departments of transportation (DOTs) on their experiences with evaluating JPCP warping and collect data for case studies, including concrete mixture design, pavement design, construction conditions, and field performance. Task 3. Synthesize the results of the literature review and survey to identify knowledge gaps related to the research objective. These gaps should be addressed in the final product or the recommended future research, as the budget permits. Task 4. Prepare the data structure, identify pavement sections, and document all potential data sources to be utilized in the study. These data sources (e.g., LTPP sites, projects conducted by state DOTs, and accelerated pavement testing sites) must be evaluated for their reliability before being utilized in the study. Task 5. Propose the research plan to be executed in Phase II to achieve the project objective. At a minimum, the research plan shall describe the research team’s approach to: Developing a rational procedure to quantify JPCP warping using field data (e.g., LTPP data); Developing, calibrating, and validating mechanistic–empirical predictive models that include the effect of slab warping on performance, which could be quantified based on internal relative humidity by considering influential factors, such as curing, construction conditions, support conditions under the slabs, physical restraints, creep, and others (the models shall be calibrated based on representative national data and be compatible with and readily implementable in the latest version of AASHTOWare PMED procedures and software); and Developing draft language for consideration by the American Association of State Highway and Transportation Officials (AASHTO) to incorporate the research results into the next update of Mechanistic–Empirical Pavement Design Guide: A Manual of Practice and the AASHTOWare PMED (herein called the AASHTO Deliverables). Task 6. Prepare Interim Report No. 1, which documents the research performed in Tasks 1 through 5, includes a data archiving and sharing plan (see Special Note B), and provides an updated work plan for the remainder of the research. The updated plan must describe the process and rationale for the work proposed for Phases II and III. Interim Report No. 1 shall be submitted no later than 9 months after the contract is awarded.
