The objective of this research is to develop the calibration procedure for the AASHTO 2002 design guide models for both flexible and rigid pavement structures for this region and to assist the state highway agencies in region in the implementation of the new Guide for pavement design and surface selection practices.

It is envisioned that this study will be accomplished through the following tasks: 1. Literature Search - A literature search will be conducted to gather detailed information on the AASHTO 2002 design guide models, and all material and performance prediction models that it contains. Special consideration will be given to the models for characterization of pavement materials and soils and the corresponding material testing procedures. At the end of the literature search, based on the findings, a calibration plan will be developed in consultation with the state-selected Project Monitor (s). 2. Pavement Performance and Material Database: At this stage of the project, a database with representative material characterization and pavement condition data for participating states in the region will be built. The process will use data published in various state research reports, construction data as well as condition data available in the pavement management systems. The database will contain information only for several pavement sections considered representative of the roads in the participating states. The sections will be new as well as rehabilitated flexible and rigid pavements. 3. Analytical Model Calibration: In this task, the statistical analysis of the data assembled in the database will be performed. This task will also aim at the calibration factors for the following relationships: - layer material parameters used in the design model (e.g. stiffness, resilient modulus) and physical material characteristics (e.g. air voids, binder content, cement content). - traffic load spectra analysis and current capability of each agency to generate input for the calibration process. - pavement performance parameters (e.g. rutting, cracking, joint faulting) and stresses and strains at the corresponding critical locations in the pavement structures under different environmental conditions. The analysis will also include the study of the reliability of the new AASHTO design method to be applicable for the road conditions in the participating states when proposed calibration factors and material parameters are used. 4. Sensitivity Toward Surface Types Under Consideration- In this task, multiple runs of rigid and flexible pavement design methods will be done to determine the sensitivity of the input variables in the design process. 5. Life Cycle Cost (LCC) Analysis- The proposed LCC analysis module is quite extensive and needs a large number of inputs. In this task, the input needs and availability will be studied in details. The feasibility of developing default parameters for some inputs will also be investigated. 6. Reporting and Training - A final report will be prepared that will give detailed information on methodology and data used for the AASHTO 2002 model calibration. The report will include recommendations on the optimum use of the AASHTO model and life cycle cost analysis methodology as well as recommended default input values for the model parameters. Training of the participating agency pavement design personnel will be conducted to ease their work in understanding and using the model, and to better inform them on the calibration work and the supporting information.

Cost per state will be $62,000. The KSDOT has funded this research project at Kansas State University and is offering to serve as lead state in a pooled fund project that would allow surrounding states and other states in the region to share information and resources.