Cochran, George

This report presents a series of testing protocols used at the Minnesota Road Research Project (Mn/ROAD), the Minnesota Department of Transportation's (Mn/DOT) pavement testing facility. This report helps establish a history of the tests conducted and testing procedures, and also serves as a reference for researchers outside of Mn/DOT to compare the values found in independent or cooperative studies to Mn/ROAD test results and procedures. The following protocols are included: -pavement condition testing plan and testing protocols -deflection test protocols -subsurface temperature testing protocols -frozen soil measurements testing protocols -traffic measurements testing protocols -material samples testing protocols -soil moisture measurements testing protocols -climate data testing protocols -bituminous testing protocols.

Pavement drainage systems have become a common addition to construction and reconstruction plans. Several types of transverse and longitudinal drains that vary in shape, size and cost are often included in designs although little is known about their performance. This study describes and evaluates the drainage characteristics and pavement performance of four drainage systems under jointed portland cement concrete pavement. Included are the Minnesota Department of Transportation (Mn/DOT) standard dense graded base. two dense graded base sections incorporating transverse drains placed under the transverse joints, and permeable asphalt stabilized base, a design which reflects current Mn/DOT drainable base thinking. All sections include longitudinal edge drains. Construction of the test sections was done during 1989. Monitoring of rainfall and drainage began in 1990 and continued through 1994. Experiment variables include drainage flows, percent of rainfall drained, time to drain, base and subgrade moisture content, and pavement and joint durability. Pavement performance evaluations will continue over the next several years. This paper presents an overview of the study, examines the data, and summarizes the findings. The study is expected to lead to improvements in the design of positive pavement drainage systems.

The recently introduced Mechanistic-Empirical Pavement Design Guide (MEPDG) and related software provide capabilities for the analysis and performance prediction of different types of flexible and rigid pavements. An important aspect of this process is the evaluation of the performance prediction models and sensitivity of the predicted distresses to various input parameters for local conditions and, if necessary, re-calibration of the performance prediction models. To achieve these objectives, the Minnesota Department of Transportation (MnDOT) and the Local Road Research Board (LRRB) initiated a study "Implementation of the MEPDG for New and Rehabilitated Pavement Structures for Design of Concrete and Asphalt Pavements in Minnesota." This report presents the results of the evaluation of default inputs, identification of deficiencies in the software, sensitivity analysis, and comparison of results to the expected limits for typical Minnesota site conditions, a wide range of pavement design features (e.g. layer thickness, material properties, etc), and the effects of different parameters on predicted pavement distresses. Since the sensitivity analysis was conducted over a span of several years and the MEPDG software underwent significant modifications, especially for flexible pavements, various versions of the MEPDG software were run. Performance prediction models of the latest version of the MEPDG 1.003 were evaluated and modified or recalibrated to reduce bias and error in performance prediction for Minnesota conditions.