blank space

South Dakota Department of Transportation
Project Synopsis

Title: Mechanistic-Empirical Pavement Design Guide Implementation Plan
Project Researcher: Katie Zimmerman, Applied Pavement Technologies
Project Manager: Daris Ormesher
Research Period: 5/15/2006 - 10/31/2007
Cost: $90,000.00

Problem Statement:A Mechanistic-Empirical (M-E) pavement design system, including elements of the Strategic Highway Research Program (SHRP) models for long-term pavement performance and materials control, is currently being presented for adoption by AASHTO. The M-E design guide elements are based on NCHRP Project (1-37A) which is a coordinated and cooperative effort to improve the state of the practice for pavement design by moving design principles from empirically based methods to mechanistic-empirical procedures.

The current pavement design method utilized by the SDDOT is extensively based on empirical standards developed by the AASHO road test conducted in the late 1950s and early 1960s. Climatic limitations, advances in material science, vehicular design changes and increased volume and weight distribution of traffic have all served to make this empirical data archaic.

The M-E design guide will tie together structural design, materials selection, and construction parameters assuring that design criteria have been met or exceeded. Many ranges of inputs are available in the system. Those that can be tailored to South Dakotas unique materials, traffic and climatic conditions will result in more effective and reliable pavement designs, extended pavement service life and thereby more cost effective investment decisions.

SDDOT needs to determine the inputs and associated resources required to implement the M-E design guide. There needs to be a cost/benefit and sensitivity analysis conducted on the design inputs, and comparison with SDDOTs current design standard inputs. A detailed implementation plan outlining necessary resources and timeline needs to be developed once the sensitivity analysis and identification of required inputs is complete.

Findings: The research effort began with a sensitivity analysis of selected inputs associated with five typical SDDOT pavement designs. These included three new construction designs (rural jointed plain concrete pavement [JPCP]; rural asphalt concrete [AC], and continuously reinforced concrete pavement [CRCP] interstate) and two rehabilitation designs (AC overlay over existing rural AC and AC overlay over rubblized rural JPCP). Over 600 runs of the MEPDG software (version 0.9) were conducted to determine how changing selected MEPDG inputs impacted pavement performance (i.e., distress and International Roughness Index [IRI]). Next, the research team ranked the investigated inputs in order of their significance to the prediction of pavement performance for each design, and identified SDDOT “target” MEPDG input levels. Finally, the research team estimated the resources needed for the SDDOT to collect the data that is needed to support the MEPDG at the target input levels. Also as part of this research, a stand alone MEPDG implementation plan was developed to outline other MEPDG-related activities that are deemed necessary over the next few years in order for the SDDOT to continue gaining valuable experience with the new MEPDG approach.

Research Objectives:
1  Identify the requirements and resources that will be needed for SDDOT to implement the AASHTO M-E Pavement Design Guide.
2  Develop AASHTO M-E Pavement Design implementation plan for SDDOT.

Research Tasks:
1  Meet with the project's technical panel to review project scope and work plan.
2  Review current literature, including other state's experiences, regarding implementation of the AASHTO M-E Pavement Design Guide.
3  Perform sensitivity analysis on all design inputs to the AASHTO M-E pavement design software for typical South Dakota site conditions. The analysis must cover the full range of inputs, including mix properties, design features, traffic loading, envir
4  Rank the design inputs in order of their effect on predicted pavement performance and determine the level of detail actually required for the numerous inputs to the program. Specify testing protocols needed to acquire the data at the specified levels
5  Describe existing SDDOT data that can be used for design inputs to the AASHTO M-E pavement design software at the required levels of detail.
6  Identify resources (staff, testing capabilities, equipment, information systems, knowledge, training etc.) needed to obtain necessary design inputs.
7  Evaluate the applicability of performance models in the AASHTO M-E pavement design guide to South Dakota conditions and identify needed development of local calibrations.
8  Prepare a detailed implementation plan that outlines elements of work necessary to utilize the AASHTO pavement design methodology at SDDOT. The plan must include but not be limited to estimated costs and recommended schedule for input acquisition, ev
9  Submit the implementation plan for review and meet with the technical panel.
10  Modify the implementation plan based on panel comments.
11  Prepare a final report and executive summary of the research methodology, findings, conclusions, and recommendations.
12  Make an executive presentation to the SDDOT Research Review Board at the conclusion of the project.

Documents Available:
blank space