Field Calibration of Fatigue Models of Cementitiously Stabilized Pavement Materials for Use in the Mechanistic-Empirical Pavement Design Guide

2019 ◽  
Vol 2673 (2) ◽  
pp. 427-435
Author(s):  
Xiaojun Li ◽  
Jingan Wang ◽  
Haifang Wen ◽  
Balasingam Muhunthan
Keyword(s):  
Field Performance ◽  
Fatigue Cracking ◽  
Pavement Design ◽  
Fatigue Properties ◽  
Bottom Up ◽  
Freeze Thaw ◽  
State Highway ◽  
Design Guide ◽  
Fatigue Model ◽  
Pavement Structures

The use of cementitiously stabilized materials (CSM), such as lean concrete, cement-stabilized aggregate, and soil stabilized with cement, lime, fly ash, or combinations thereof in the subgrade, sub-base, and base layers of flexible and rigid pavement structures, is a widely accepted practice by many state highway agencies. However, the bottom-up fatigue cracking models of cementitiously stabilized layers (CSL) described in the AASHTO Interim Mechanistic-Empirical Pavement Design Guide Manual of Practice (referred to as the MEPDG) have not been calibrated for CSM based on their field performance. In addition, top-compression fatigue as well as the effects of increases in the modulus and strength values of CSM over time, erosion, and freeze–thaw and wet–dry cycles on the fatigue properties of CSM are not considered in the MPEDG. To address these deficiencies, this research calibrated the bottom-up fatigue model, and developed and calibrated the top-compression fatigue model, with consideration of modulus and strength growth, erosion, and freeze–thaw and wet–dry cycles. Reasonable correlations between the predicted modulus values and measured modulus values are found for CSL. Further study is needed to refine the calibration and validate the models based on a larger population of field data that covers different material types, climatic zones, and traffic conditions.

DESIGNING A FLEXIBLE PAVEMENT DESIGN TOOL USING THE MEPDG APPROACH

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rahma Ibrahim Ibrahim ◽  
Mostafa Hossam ElDin Ali ◽  
Omar Sameh El Marakby ◽  
Noura Mohamed Soussa ◽  
Yomna Mohamed Abdel Aziz ◽  
...  
Keyword(s):  
Fatigue Cracking ◽  
Flexible Pavement ◽  
Design Tool ◽  
Pavement Design ◽  
Analysis Software ◽  
Complex Design ◽  
Expected Performance ◽  
Design Guide ◽  
Pavement Structures ◽  
Two Phases

The Mechanistic-Empirical principles were used to develop a software, known as AASHTOWare Pavement ME Design. It is a design and analysis software, designed according to the latest AASHTO standards, the Mechanistic Empirical Pavement Design Guide MEPDG approach, which identifies the causes of stresses in pavement structures and forecasts the pavement’s performance throughout its lifespan. Due to its sophisticated complex design, the AASHTOware is of constrained availability in the market. However, due to its significance and its ability to revolutionize the industry, this paper discusses a proposed flexible pavement design tables based on the MEPDG that is founded on Egyptian traffic loadings and material characteristics. This study is divided into two phases; the first is concerned with evaluating the performance of an actual Egyptian roadway pavement design while the second aims to develop a new design tool integrating traffic, climate, and material. The research results showed the poor expected performance of the studied roadway pavement in terms of rutting and fatigue cracking. This research also provided a basic flexible pavement design tables using the MEPDG approach and based on the Egyptian materials, climatic and loading conditions.

Implementation Initiatives of the Mechanistic–Empirical Pavement Design Guides in Indiana

2005 ◽  
Vol 1919 (1) ◽  
pp. 142-151 ◽  
Author(s):  
Tommy Nantung ◽  
Ghassan Chehab ◽  
Scott Newbolds ◽  
Khaled Galal ◽  
Shuo Li ◽  
...  
Keyword(s):  
Pavement Design ◽  
Sensitivity Analyses ◽  
Pavement Performance ◽  
Design Parameters ◽  
State Highway ◽  
Design Guide ◽  
Input Parameters ◽  
Pavement Structures ◽  
State Highway Agencies ◽  
Empirical Design

The release of the Mechanistic–Empirical Design Guide for New and Rehabilitated Pavement Structures (M-E design guide) generated a new paradigm for designing and analyzing pavement structures. It is expected to replace the commonly used empirical design methodologies. The M-E design guide uses a comprehensive suite of input parameters deemed necessary to design pavements with high reliability and to predict pavement performance and distresses realistically. However, the considerable amount of input needed and the selection of the corresponding reliability level for each might present state highway agencies with complexities and challenges in its implementation. An overview is presented of ongoing investigative studies, sensitivity analyses, and preimplementation initiatives conducted by the Indiana Department of Transportation (INDOT) in an effort to accelerate the adoption of the new pavement design guide by efficiently using existing design parameters and determining those parameters that influence the predicted performance the most. Once the sensitive inputs are identified, the large amount of other required design input parameters can be significantly reduced to a manageable level for implementation purposes. A matrix of trial runs conducted with the M-E design guide software suggests that a higher design level input does not necessarily guarantee a higher accuracy in predicting pavement performance. The software runs also confirmed the need to use input values obtained from local rather than national calibration. Such findings are important for state highway agencies such as INDOT in drafting initiatives for implementing the M-E design guide.

Use of Long-Term Pavement Performance Data to Develop Traffic Defaults in Support of Mechanistic-Empirical Pavement Design Procedures

2003 ◽  
Vol 1855 (1) ◽  
pp. 176-182 ◽  
Author(s):  
Weng On Tam ◽  
Harold Von Quintus
Keyword(s):  
Pavement Design ◽  
Vehicle Classification ◽  
Pavement Performance ◽  
Traffic Data ◽  
Design Procedures ◽  
Load Spectra ◽  
State Highway ◽  
Pavement Structures ◽  
Empirical Design

Traffic data are a key element for the design and analysis of pavement structures. Automatic vehicle-classification and weigh-in-motion (WIM) data are collected by most state highway agencies for various purposes that include pavement design. Equivalent single-axle loads have had widespread use for pavement design. However, procedures being developed under NCHRP require the use of axle-load spectra. The Long-Term Pavement Performance database contains a wealth of traffic data and was selected to develop traffic defaults in support of NCHRP 1-37A as well as other mechanistic-empirical design procedures. Automated vehicle-classification data were used to develop defaults that account for the distribution of truck volumes by class. Analyses also were conducted to determine direction and lane-distribution factors. WIM data were used to develop defaults to account for the axle-weight distributions and number of axles per vehicle for each truck type. The results of these analyses led to the establishment of traffic defaults for use in mechanistic-empirical design procedures.

Incorporation of Endurance Limit in the Mechanistic-Empirical Flexible Perpetual Pavement Design

2018 ◽  
Vol 2672 (40) ◽  
pp. 108-121 ◽  
Author(s):  
Sheng Hu ◽  
Sang-Ick Lee ◽  
Lubinda F. Walubita ◽  
Fujie Zhou ◽  
Tom Scullion
Keyword(s):  
Endurance Limit ◽  
Design Method ◽  
Field Performance ◽  
Fatigue Cracking ◽  
Climatic Conditions ◽  
Influential Factors ◽  
Pavement Design ◽  
Design System ◽  
Viscoelastic Continuum Damage ◽  
Perpetual Pavement

In recent years, there has been a push toward designing long-lasting thick hot mix asphalt (HMA) pavements, commonly referred to as a perpetual pavements (PP). For these pavements, it is expected that bottom-up fatigue cracking does not occur if the strain level is below a certain limit that is called the HMA fatigue endurance limit (EL). This paper proposed a mechanistic-empirical PP design method based on this EL concept. The ELs of 12 HMA mixtures were determined using simplified viscoelastic continuum damage testing and the influential factors were comparatively investigated. It was found that HMA mixtures seem to have different EL values based on mix type and test temperatures. There is not just a single EL value that can be used for all mixtures. Thus, default EL criteria for different mixtures under different climatic conditions were developed and incorporated into the Texas Mechanistic-Empirical Flexible Pavement Design System (TxME). As a demonstration and case study, one Texas PP test section with weigh-in-motion traffic data was simulated by TxME. The corresponding TxME inputs/outputs in terms of the PP structure, material properties, traffic loading, environmental conditions, and ELs were demonstrated. The corresponding TxME modeling results were consistent with the actual observed field performance of the in-service PP section.

Mechanistic–empirical damage analysis and impacts of reduced tire pressure on thaw weakened flexible pavements using the AI and MEPDG models

2012 ◽  
Vol 39 (7) ◽  
pp. 812-823
Author(s):  
Leonnie Kavanagh ◽  
Ahmed Shalaby
Keyword(s):  
Fatigue Damage ◽  
Flexible Pavements ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
T Test ◽  
Pavement Design ◽  
Damage Analysis ◽  
Confidence Limits ◽  
Tire Pressure ◽  
Design Guide

A damage analysis was conducted on a spring weight restricted flexible pavement to quantify the effects of reduced tire pressure on pavement life and to compare the damage predictions from the Asphalt Institute (AI) and the Mechanistic Empirical Pavement Design Guide (MEPDG) models. The models were used to predict the number of repetitions to fatigue and rutting failure at three maximum loads and at high and low tire pressures. Based on the results, the AI and MEPDG predictions were statistically different for both fatigue cracking and rutting damage, based on the t-test at 95% confidence limits. The AI model predicted 31% lower fatigue damage than the MEPDG, but 56% higher rutting damage. However, both models produced similar trends in predicting the relative effects of reduced tire pressure and load levels on pavement life. The methodology and results of the analysis are presented in this paper.

scholarly journals Mechanistic-empirical approach to evaluate new and rehabilitated flexible pavements

2021 ◽  
Author(s):  
Wais Mehdawi
Keyword(s):  
Flexible Pavements ◽  
Empirical Method ◽  
Pavement Design ◽  
Empirical Approach ◽  
Integrated Analysis ◽  
Highway Traffic ◽  
Design Guide ◽  
The Difference ◽  
Pavement Structures ◽  
Empirical Design

The Mechanistic-Empirical Design provides more insight into pavement behaviour and performance than the 1993 AASHTO empirical method. The new Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under the National Corporation Highway Research Program (NCHRP) 1-37A. A hierarchical approach is employed upon traffic, climate and materials input to produce pavement performance predictions of smoothness and numver of distress types. One of the most significant changes offered in the Mechanistic Empirical Design Guide (ME PDG) is the difference in the method used to account for highway traffic loading. Traffic volume and traffic loads, the two most important aspects required to characterize traffic for pavement design are treated separately and independently and its use-oriented computational software implements an integrated analysis approach for predicting pavement condiditon over time that accounts for the interaction of traffic, climate and pavement structures. The recently developed guide for mechanistic-empirical (M-E) design of new and rehabilitated pavement structures will change the way in which pavements are designed by replacing the traditional emprirical design approach in the AASHTO 1983 Guide. The M-E Pavement Design Guide will allow pavement designers to make better-informaed decisisions and take cost-effect advantage of new materials and features. However, the proposed design guide is substantially more complex than the 1983 AASHTO design guide. It requires more imput values from the designer. There is limited availability of the data for many MEPDG inputs. This project report presents the Mechanistic-Empirical approach of Pavement Design for New and Rehabilitated Flexible Pavements using the new ME PDG. The main objectives of the report are: (1)to demonstrated how the Mechanistic-Empirical design of pavement is more precise than the existing empirical method, (2)to explain the software input and output parameters, (3)to present a complete overview of the M-E design process and to gain a thorough understanding of the materials, traffic, climate and pavement design inputs required for M-E design.

Mechanistic-Empirical Flexible Pavement Design: An Overview

1996 ◽  
Vol 1539 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Marshall R. Thompson
Keyword(s):  
Task Force ◽  
New Technology ◽  
Flexible Pavement ◽  
Pavement Design ◽  
Analysis And Design ◽  
Design Procedures ◽  
State Highway ◽  
Pavement Structures ◽  
Available Technology ◽  
State Highway Agencies

Activities associated with the development of the revised AASHTO Guide for the Design of Pavement Structures (1986 edition) prompted the AASHTO Joint Task Force on Pavements (JTFOP) recommendation to immediately initiate research with the objective of developing mechanistic pavement analysis and design procedures suitable for use in future versions of the AASHTO guide. The mechanistic-empirical (M-E) principles and concepts stated in the AASHTO guide were included in the NCHRP 1-26 (Calibrated Mechanistic Structural Analysis Procedures for Pavements) project statement. It was not the purpose of NCHRP Project 1-26 to devote significant effort to develop new technology but to assess, evaluate, and apply available M-E technology. Thus, the proposed processes and procedures were based on the best demonstrated available technology. NCHRP Project 1-26 has been completed and the comprehensive reports are available. M-E flexible pavement design is a reality. Some state highway agencies (Kentucky and Illinois) have already established M-E design procedures for new pavements. M-E flexible pavement design procedures have also been developed by industry groups (Shell, Asphalt Institute, and Mobil). The AASHTO JTFOP continues to support and promote the development of M-E procedures for pavement thickness design and is facilitating movement toward an M-E procedure. The successful and wide-scale implementation of M-E pavement design procedures will require cooperating and interacting with various agencies and groups (state highway agencies, AASHTO—particularly the AASHTO JTFOP, FHWA—particularly the Pavement Division and Office of Engineering, and many material and paving association industry groups). It is not an easy process, but it is an achievable goal.

Calibration of Alligator Fatigue Cracking Model for 2002 Design Guide

2005 ◽  
Vol 1919 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Mohamed M. El-Basyouny ◽  
Matthew Witczak
Keyword(s):  
Reference Model ◽  
Design Procedure ◽  
Fatigue Cracking ◽  
The United States ◽  
Bottom Up ◽  
Traffic Loads ◽  
Mechanistic Approach ◽  
Linear Layer ◽  
Design Guide ◽  
Base Reference

In AASHTO's 2002 design guide, the classic fatigue cracking mechanism, which normally initiates at the bottom of the asphalt layer and propagates to the surface (bottom-up cracking), was studied. The prediction of bottom-up alligator fatigue cracking was based on a mechanistic approach to calculate stress and strain. An empirical approach then related these strains to fatigue damage in pavement caused by traffic loads. To provide credibility to the new design procedure, the theoretically predicted distress models must be calibrated to “real-world” performance. In fact, calibration of these distress models is considered to be the most important activity to facilitate implementation, acceptance, and adoption of the design procedure and to establish confidence in the entire procedure. The procedure followed for the national calibration of the alligator fatigue–cracking model used in the AASHTO 2002 design guide is discussed. This calibration study used data from all over the United States, with different environments, material, and traffic. A total of 82 pavement sections from 24 different states were used in the calibration. Tensile strain at the bottom of each asphalt layer was calculated using a linear layer elastic analysis procedure. The initial (base) reference model used in the calibration was the Asphalt Institute MS-1 model. This model was used to compute the damage caused by traffic loads and pavement structure. Predicted damage was then correlated to the measured fatigue cracking in the field, and a transfer function was obtained for the alligator fatigue–cracking distress.

scholarly journals Truck Traffic and Load Spectra of Indiana Roadways for the Mechanistic-Empirical Pavement Design Guide

2020 ◽  
Author(s):  
Jieyi Bao ◽  
Xiaoqiang Hu ◽  
Cheng Peng ◽  
Yi Jiang ◽  
Shuo Li ◽  
...  
Keyword(s):  
Urban Areas ◽  
Critical Role ◽  
Fatigue Cracking ◽  
Pavement Design ◽  
Easy Access ◽  
Traffic Data ◽  
Truck Traffic ◽  
Load Spectra ◽  
Design Guide ◽  
Input Module

The Mechanistic-Empirical Pavement Design Guide (MEPDG) has been employed for pavement design by the Indiana Department of Transportation (INDOT) since 2009 and has generated efficient pavement designs with a lower cost. It has been demonstrated that the success of MEPDG implementation depends largely on a high level of accuracy associated with the information supplied as design inputs. Vehicular traffic loading is one of the key factors that may cause not only pavement structural failures, such as fatigue cracking and rutting, but also functional surface distresses, including friction and smoothness. In particular, truck load spectra play a critical role in all aspects of the pavement structure design. Inaccurate traffic information will yield an incorrect estimate of pavement thickness, which can either make the pavement fail prematurely in the case of under-designed thickness or increase construction cost in the case of over-designed thickness. The primary objective of this study was to update the traffic design input module, and thus to improve the current INDOT pavement design procedures. Efforts were made to reclassify truck traffic categories to accurately account for the specific axle load spectra on two-lane roads with low truck traffic and interstate routes with very high truck traffic. The traffic input module was updated with the most recent data to better reflect the axle load spectra for pavement design. Vehicle platoons were analyzed to better understand the truck traffic characteristics. The unclassified vehicles by traffic recording devices were examined and analyzed to identify possible causes of the inaccurate data collection. Bus traffic in the Indiana urban areas was investigated to provide additional information for highway engineers with respect to city streets as well as highway sections passing through urban areas. New equivalent single axle load (ESAL) values were determined based on the updated traffic data. In addition, a truck traffic data repository and visualization model and a TABLEAU interactive visualization dashboard model were developed for easy access, view, storage, and analysis of MEPDG related traffic data.

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