The role of the environment in pavement deterioration is not well understood. Temperature, moisture, wind, sunlight, and frost can all affect the material properties of the different pavement layers. Deterioration in turn affects the long-term ride performance and structural capacity of the pavement. As an example, Minnesota has historically designed pavement structures at least 30 inches above the subgrade to minimize frost heave and therefore maintain an acceptable ride. Is this design appropriate? The Minnesota Road Research Facility (MnROAD) provides an excellent source of information that can be used to define the deterioration modes that are related to environmental effects and/or the combined effects of materials and environment. In addition, the pavement management systems in Minnesota and other states add additional information related to pavement performance over time. The environmental effects of seasonal frost heave on IRI have been studied over time at MnROAD, and there is an opportunity for further analysis on this and other topics. The ability to design pavements to withstand the long-term effects of the environment is limited by the understanding of the how the pavements deteriorate. A perceived benefit of this study would be to enhance the ability to design and construct long life pavements, taking into consideration component material properties, that can withstand the long-term effects of the environment. Related studies include: . TPF-5(013): Effect of Multiple Freeze-Thaw Versus Deep Frost Penetration on Pavement Performance (Nichols Consulting) . NCHRP 1-34D: Effects of Subsurface Drainage on Performance of Asphalt and Concrete Pavements: Further Evaluation and Analysis of LTPP SPS-1 and SPS-2 Field Sections (Kathleen T. Hall) . NCHRP 9-23: Environmental Effects in Pavement Mix and Structural Design Systems (Arizona State University) . TPF-5(019): Full-Scale Accelerated Performance Testing for Superpave and Structural Validation (FHWA) . TPF 928: Geocomposite Capillary Barrier Drain (GCBD) for Limiting Moisture Changes in Pavements: Product Application (Mn/DOT) . TPF-5(079): Implementation of the 2002 AASHTO Design Guide for Pavement Structures (Kansas) . NCHRP 1-40B: Local Calibration Guidance for the Recommended Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures (ARA) . TPF-5(066): Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements (Iowa) . TPF-5(121): Monitoring and Modeling of Pavement Response and Performance (Ohio) . SPR-2(208): Pavement Subgrade Performance Study (CRREL) . NCHRP 10-66: Predicting In-Service Performance of Flexible Pavements from Accelerated Pavement Testing (J.B. Metcalf) . TPF-5(010): Structural Improvement of Flexible Pavements Using Geosynthetics for Base Course Reinforcements (CRREL) The data collected at MnROAD provides a unique opportunity to evaluate the role environment and loadings have on the development of the pavement distresses, including change in longitudinal profile.

A wealth of data has been collected from the MnROAD project, including environmental, traffic, and pavement performance information. However, a focused study on how the environment affects material properties and pavement performance has not yet taken place. The goal of this research is to comb through years of data from existing MnROAD and pavement management sections to correlate environmental and performance data.

This project may consist of the following activities: . Work Plan: The work plan for this pooled fund study will ultimately be developed by the participating organizations. . Monitor environmental, traffic, and pavement performance data over time and analyze the results: o Frost pins o Ride (IRI) o Pavement material properties (HMA, PCC, base, subgrade) o Traffic (live interstate, 80K truck, 102K truck) o Pavement performance (cracking, rutting, faulting, etc.) and modes of deterioration . Examine the effects base, subbase, and subgrade materials have on long-term ride performance: Preliminary analysis indicates that long-term soil volume changes contribute to changes in pavement profile that is independent from the effects of traffic. These changes appear to be material dependent (type, density, moisture). Understanding these relationships will enable pavements to be designed to minimize the soil volume changes and the impact on ride. . Design Guide Modeling & Validation: The material properties for all pavement layers will be modeled in the new mechanistic-empirical design procedure. Statistical analysis methods will be used to identify material characteristics that relate to environmental degradation of materials. . Pooled Fund Travel: Money for each state to travel to discuss the progress of the study. . Data Analysis & Reports: Work done under a research contract will develop interim and final reports that document the findings of this study.

Mn/DOT along with other participating states are asked to contribute $25,000 per year for 2 years to fund the research proposed in this pooled fund study