Iowa Experience on Local Calibration of AASHTOWare Pavement ME Design (PMED) for Jointed Plain Concrete Pavements

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement performance models and the associated AASHTOWare pavement ME design (PMED) software are nationally calibrated using design inputs and distress data largely obtained from National Long-Term Pavement Performance (LTPP) to predict Jointed Plain Concrete Pavement (JPCP) performance measures. To improve the accuracy of nationally-calibrated JPCP performance models for various local conditions, further calibration and validation studies in accordance with the local conditions are highly recommended, and multiple updates have been made to the PMED since its initial release in 2011, with the latest version (i.e., Ver. 2.5.X) becoming available in 2019. Validation of JPCP performance models after such software updates is necessary as part of PMED implementation, and such local calibration and validation activities have been identified as the most difficult or challenging parts of PMED implementation. As one of the states at the forefront of implementing the MEPDG and PMED, Iowa has conducted local calibration of JPCP performance models extending from MEPDG to updated versions of PMED. The required MEPDG and PMED inputs and the historical performance data for the selected JPCP sections were extracted from a variety of sources and the accuracy of the nationally-calibrated MEPDG and PMED performance prediction models for Iowa conditions was evaluated. To improve the accuracy of model predictions, local calibration factors of MEPDG and PMED performance prediction models were identified and gained local calibration experiences of MEPDG and PMED in Iowa are presented and discussed here to provide insight of local calibration for other State Highway Agencies (SHAs).

Evaluation of Structural Condition of Flexible Pavement Using The AASHTO 1993 and The MEPDG 2008 Method (Case Study: Cipatujah-Kalapagenep-Pangandaran National Road)

Flexible pavement on Cipatujah-Kalapagenep-Pangandaran National Road has a structural damage which marked by potholes and cracks on the pavement caused by excessive load trucks, so the pavement needs an overlay to improve the pavement condition. This analysis using AASHTO 1993 and MEPDG 2008 method. These methods used because the MEPDG 2008 was developed from AASHTO 1993 method, so the output will be more economic. But, the MEPDG 2008 has not applied yet in Indonesia, so the method will be studied to determine the method feasibility to be applied in Indonesia. This research was analyzed with two skenarios of CESAL, four trial thicknesses, and three CBR numbers. The overlay thickness value using the AASHTO 1993 was at 10 cm and 11 cm for scenario 1 and 2, while the overlay thickness using the MEPDG 2008 was at 10 cm for the two scenarios. The result from AASHTO 1993 was chosen because the MEPDG 2008 needs to studied further yet about suitable calibration factor for Indonesian pavement condition. The cause of difference result are structural damage assessment for AASHTO 1993 method based on deflection value from FWD while MEPDG 2008 method based on stresses and strains respond, material characteristics, and local calibration. Keywords: AASHTO 1993, MEPDG 2008, stress and strain response, FWD deflection value, local calibration factors, overlay thickness. Abstrak Perkerasan lentur jalan Nasional Cipatujah-Kalapagenep-Pangandaran mengalami kerusakan struktural yang ditandai dengan lubang dan retak pada perkerasan badan jalan yang disebabkan oleh truk pengangkut pasir yang memiliki beban berlebih, sehingga diperlukan penambahan tebal lapis tambah pada perkerasan jalan eksisting untuk mengembalikan kondisi kemantapan jalan. Dalam penelitian ini dilakukan analisis terhadap kondisi struktural perkerasan jalan lentur eksisting menggunakan Metoda AASHTO 1993 dan Metoda MEPDG 2008 dengan pertimbangan bahwa MEPDG 2008 merupakan pengembangan dari AASHTO 1993. Namun, Metoda MEPDG 2008 belum diterapkan di Indonesia, maka perlu dilakukan kajian awal untuk mengetahui kelayakan metoda tersebut diterapkan di Indonesia. Analisis ini menggunakan dua skenario nilai CESAL, empat macam tebal dan tiga macam nilai CBR. Berdasarkan hasil analisis, diperoleh tebal overlay menggunakan metoda AASHTO 1993 sebesar 10 cm dan 11 cm untuk skenario 1 dan 2, sedangkan tebal overlay menggunakan metoda MEPDG 2008 diperoleh tebal overlay sebesar 10 cm untuk kedua skenario. Namun dalam penelitian ini dipilih hasil dari metoda AASHTO 1993 dikarenakan MEPDG 2008 masih memerlukan kajian lanjut terkait faktor kalibrasi berdasarkan kondisi perkerasan di Indonesia. Dari penelitian diketahui faktor yang menyebabkan perbedaan hasil adalah Metoda AASHTO 1993 berdasarkan nilai lendutan FWD, sedangkan MEPDG 2008 berdasarkan respon tegangan dan regangan, karakteristik material, dan kalibrasi lokal. Kata-kata kunci: AASHTO 1993, MEPDG 2008, respon tegangan dan regangan, nilai defleksi FWD, faktor kalibrasi lokal, ketebalan lapisan.

A Machine-Learning Approach for Extracting Modulus of Compacted Unbound Aggregate Base and Subgrade Materials Using Intelligent Compaction Technology

This study presents a rigorous approach for the extraction of the modulus of soil and unbound aggregate base materials for quality management using intelligent compaction (IC) technology. The proposed approach makes use of machine-learning methods in tandem with IC technology and modulus-based spot testing as a local calibration process to estimate the mechanical properties of compacted geomaterials. A calibrated three-dimensional finite element (FE) model that simulates the proof-mapping process of compacted geomaterials was used to develop a comprehensive database of responses of a wide range of single and two-layered geosystems. The database was then used to develop different inverse solvers using artificial neural networks for the estimation of the modulus from the characteristics of the roller and information about the geomaterials. Several instrumented test sites were used for the evaluation and validation of the inverse solvers. The proposed approach was found promising for the extraction of the modulus of compacted geomaterials using IC. The accuracy of the inverse solvers is enhanced if a local calibration process is incorporated as part of a quality management program that includes the use of in situ measurements using modulus-based test devices and laboratory resilient modulus testing. Moreover, compaction uniformity plays a key role in the retrieval of the modulus of geomaterials with certainty. The proposed approach fuses artificial intelligence with mechanistic solutions to position IC as a technology that is well suited for the quality management of compacted materials.

Methodology development and local calibration of MEPDG permanent deformation models for Ontario's flexible pavements.

The AASHTO-supported interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was published in 2008 for trial use. However, local calibration of the empirical distress models in the design guide has been an essential exercise for any transportation agency before it formally adopts the MEPDG for practical design use. Nevertheless, a universally agreed upon local calibration methodology using historical pavement performance data from field evaluation has not been available. This research focuses on permanent deformation or rutting models in MEPDG and presents a layer-by-layer longitudinal local calibration process at the DARWin-METM platform coupled with Excel Macros. Using the best input data available, many of Level 3 accuracy, the study performs local calibration for 10 reconstructed and 19 rehabilitated flexible pavement sections. Further, this thesis statistically evaluated the level-3 pre-overlay rut value for rehabilitated flexible pavements in Ontario. A comparison of the longitudinal calibration and pooled local calibration demonstrated the importance of the longitudinal calibration in the quantification of uncertainties involved in local calibration.

Local calibration of MEPDG for Superpave Pavements in Ontario : Enhance rutting calibration and preliminary study on IRI model

The AASHTO Mechanistic-Empirical Pavement Design Guide requires local calibration to account for local conditions, materials, and engineering practices. Previous local calibration studies in Ontario focused mainly on permanent deformation models for pavement rutting. The objectives of this study are twofold. First, to provide an enhanced calibration for the rutting models by using more vigilantly cross-verified input data and updated observed rutting data. Second, to perform a trial calibration for the international roughness index (IRI) model by considering three different calibration methods. Cracking models calibration, being performed by another colleague, has not yet been finalized; therefore, the IRI model calibration cannot be finalized in this study. Based upon 63 Superpave sections, the local calibration coefficients were found to be βAC = 1.7692, βT = 1.0, βN = 0.6262, βGB = 0.0968 and βSG = 0.2787 , which reduced the standard deviation of residuals to a value of 1 mm. The IRI calibration study found that the initial IRI value plays an important role in the calibration. Keywords: International Roughness Index (IRI) model; local calibration; Mechanistic-Empirical Pavement Design Guide (MEPDG); rutting model; Superpave.

Database Development For Ontario's Local Calibration Of Mechanistic – Empirical Pavement Design Guide (MEPDG) Distress Models

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) includes empirical distress models that need both global and local calibrations. The local calibration requires developing a database that would reflect local environments, design and maintenance practices in a particular jurisdictional region. The objective of the thesis is to develop a pavement database for local calibration before the MEPDG is to be implemented in Ontario. The database involves a hierarchical framework of the input parameters required for DARWin-ME, and the measured performance data are based on the MTO’s PMS-2. To demonstrate the validity of the developed database a preliminary local calibration including clustering analysis is carried out for the IRI and total rutting. The calibration-validation analysis suggests that the IRI model can be best clustered based on the geographical zone whereas the highway functional class is the best clustering parameter for rutting during the local calibration.

Database Development For Ontario's Local Calibration Of Mechanistic – Empirical Pavement Design Guide (MEPDG) Distress Models

The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) includes empirical distress models that need both global and local calibrations. The local calibration requires developing a database that would reflect local environments, design and maintenance practices in a particular jurisdictional region. The objective of the thesis is to develop a pavement database for local calibration before the MEPDG is to be implemented in Ontario. The database involves a hierarchical framework of the input parameters required for DARWin-ME, and the measured performance data are based on the MTO’s PMS-2. To demonstrate the validity of the developed database a preliminary local calibration including clustering analysis is carried out for the IRI and total rutting. The calibration-validation analysis suggests that the IRI model can be best clustered based on the geographical zone whereas the highway functional class is the best clustering parameter for rutting during the local calibration.

Local calibration of MEPDG rutting model for Ontario’s Superpave pavements

The rutting models in the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) have been calibrated to Ontario’s conditions for flexible pavements of Marshall mixes, and have yet to be calibrated for the Superpave materials. This study differs from previous studies in several counts: First, the local calibration database included both Superpave and Marshall mixes. Second, two of the five local calibration parameters (the temperature and traffic exponents) were pre-fixed based on a secondary study of the NCHRP 719 report. Third, both cross-sectional and longitudinal calibrations were performed and compared. It was concluded that the Superpave and Marshall mix pavements should be separately treated in the local calibration and that the cross-sectional and longitudinal calibrations behaved drastically differently in terms of residual errors. A set of local calibration parameters were recommended for future pavement design. It was recommended that trench investigations be done to further validate the results from the study.

Methodology development and local calibration of MEPDG permanent deformation models for Ontario's flexible pavements.

The AASHTO-supported interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was published in 2008 for trial use. However, local calibration of the empirical distress models in the design guide has been an essential exercise for any transportation agency before it formally adopts the MEPDG for practical design use. Nevertheless, a universally agreed upon local calibration methodology using historical pavement performance data from field evaluation has not been available. This research focuses on permanent deformation or rutting models in MEPDG and presents a layer-by-layer longitudinal local calibration process at the DARWin-METM platform coupled with Excel Macros. Using the best input data available, many of Level 3 accuracy, the study performs local calibration for 10 reconstructed and 19 rehabilitated flexible pavement sections. Further, this thesis statistically evaluated the level-3 pre-overlay rut value for rehabilitated flexible pavements in Ontario. A comparison of the longitudinal calibration and pooled local calibration demonstrated the importance of the longitudinal calibration in the quantification of uncertainties involved in local calibration.