Ncat report 14 04 flexible pavement design state of. Geotechnical aspects of pavements reference manual. Evaluation of nchrp 7a rigid pavement design software. The nchrp 1 37a research program found that these thermal movements have a significant impact on concrete pavement performance, and integrated the use of cte values into the mechanisticempirical pavement design guide mepdg.
The development of the mechanisticempirical pavement design guide mepdg under national cooperative highway research program nchrp projects 7a and 140d has significantly improved the ability of pavement designers to model and simulate the effects of the combination of traffic and. Development of the 2002 guide for the design of new and rehabilitated pavement structures consisted of applied research associates, inc. Task force on pavements, in cooperation with the national cooperative highway research program nchrp and the federal highway administration fhwa, sponsored the development of an me pavement design procedure under nchrp project 1 37a. The objectives of this study are 1 to compare flexible pavement designs and performance between the empirical 1993 aashto pavement design guide and the mechanisticempirical. Following the direction of our parent organization the national academy of sciences, engineering, and medicine, the majority of our staff are working from home, until at least may 1. At the time of the nchrp 7a development, it was judged that no suitable. Acknowledgment of sponsorship this work was sponsored by the american association of state highway and transportation officials, in cooperation with the federal highway administration, and was conducted in the national cooperative highway research program, which is administered by the transportation research board of the national research council. These values are adjusted internally within the nchrp 1 37a design guide software for environmental effects and then converted into an average monthly effective kvalue for structural response calculation and damage analysis. Processed traffic data using trafload software as an input for nchrp 1 37a software, mechanisticempirical pavement design guide mepdg for new york state department of transportation nysdot. The products developed under nchrp 1 37a have provided advancements in pavement design practices and work is continuing under nchrp, fhwa and various state agencies. Results of nchrp work are often adopted by aashto, state dots, and other organizations. The purpose of this project was to develop design methods for geosynthetic reinforced flexible pavements that are compatible with the methods being developed in nchrp project 1 37a. Guide for mechanistic empirical design purdue engineering.
In 2004, nchrp 7a was completed and delivered a mechanisticempirical pavement design guide and accompanying software. The application of traffic forecasting and trip generation. Development of the 2002 guide for the design of new. Analysis of critical structure responses for flexible pavements in nchrp 1 37a mechanisticempirical pavement design guide. In both cases, the nchrp 1 37a software automatically preprocesses all of the input data required for the analysis e. Transportation research board of the national academies, washington, d. The pavement design guide is provided in an adobe pdf format that is readonly, nonsave, nonprintable, and noneditable. Information that will be incorporated into the guide and the topics that need adjustments will be identified, and appropriate language for use in the guide will be developed. Mar 30, 2004 the overall objective of the guide for the mechanisticempirical design of new and rehabilitated pavement structures referred to hereinafter as the design guide is to provide the highway community with a stateofthepractice tool for the design of new and rehabilitated pavement structures, based on mechanisticempirical principles. The overall research was divided into three major phases. Concrete coefficient of thermal expansion system gilson co. Strategic plan of the texas department of transportation for. At this time the pavement performance can be investigated using nchrp 1 37a and vesys models. A decision has been made not to pursue further work under project 1 37.
Implementation of the aashto mepdg in colorado jay goldbaum, p. The paper presents results of a sensitivity study that has been performed on the nchrp 1 37a software. Aashtoware pavement me design pavement design software used to analyze and design pavements based on me principles developed under nchrp 1 37a. Future plans for aashto me pavement design software. The design guide developed under national cooperative highway.
By july 31, 2002, nchrp project 1 37a will deliver the 2002 guide for the design of new and rehabilitated pavement structures accompanied by the necessary computational software, for adoption and distribution by aashto. Implementation of the nchrp 7a design guide final report. Design scenarios were then run through the 7a design software and. Typically the critical damage location flipped from bottomup to topdown around an ebitd level of 20 to 25of due to unsupported areas of the slab, axle spacing.
The nchrp 7a design software takes all of these traffic inputs and. Nchrp 7 development of the 2002 guide for the design of. Ce 755 highway pavement design engineering online nc. The michigan department of transportation mdot is currently working towards implementing the new aashtoware me pavement design software. The software was freely available, though considered a beta. Nchrp project 01 37a development of the 2002 guide for the design of new and rehabilitated. Implementing mechanistic empirical pavement design and.
Implementation of the nchrp 1 37a design guide final report. The overall objective of nchrp project 1 37a is to develop and deliver the 2002 guide for design of new and rehabilitated pavement structures, based on mechanisticempirical principles, accompanied by the necessary computational software, for adoption and distribution by aashto. In both cases, the nchrp 7a software automatically preprocesses all of the input data required for the analysis e. Development of the guide was undertaken at a request by the aashto joint task force on pavements. Nchrp 9 software lcreates required nchrp 7a data sets, for example the number of axles per truck by type of axle for each class of trucks seasonal factors from continuous classifier data twrg load distributions from load spectra. Itd implementation plan for mepdg bayomy and elbadawy. Mepdg was developed through the national cooperative highway research program nchrp in the. The calibrated faulting and roughness models are able to present the typical performance of wsdot pcc pavements. Nchrp 1 37a initiative is a significant advancement in pavement design. Nchrp 1 37a design guide nchrp 1 37 development of the 2002 guide.
Analysis of critical structure responses for flexible. Chapter two mechanisticempirical pavement design guide. The overall objective of nchrp project 7a is to develop and deliver the 2002 guide for design of new and rehabilitated pavement structures, based on mechanisticempirical principles, accompanied by the necessary computational software, for adoption and distribution by aashto. The calibrated models in nchrp 1 37a software can be used by wsdot. Nchrp 7 development of the 2002 guide for the design. Improvements that require a major research effort will not be appropriate for the 2002 guide. Nchrp 1 39 lrequired traffic loads are defined by the nchrp 1 37a project software lnchrp 1 39 supplies a more robust mechanism to enter that data l9 software converts traffic monitoring data into pavement design inputs. Researchers are now incorporating the latest advances in pavement design into the new mechanisticempirical pavement design guide mepdg, developed under the national cooperative highway research program nchrp 1 37a project and adopted and published by aashto. After 15 years from the initiation of the nchrp 1 37a project, the mepdg developed under that study has been adopted by the aashto and is in the process of adoption by many transportation agencies. Me pavement 30 design guide convenient input layout general information inputs. Guide for mechanisticempirical design new and rehabilitated pavement structures introduction. Characterization of louisiana asphalt mixtures using simple performance tests and mepdg 5.
Acknowledgements the research team for nchrp project 1 37a. Chapter two mechanisticempirical pavement design guide and. Recommended mechanisticempirical pavement design guide and. Nchrp 7a design guide nchrp 7 development of the 2002 guide. Characterization of louisiana asphalt mixtures using april. Related specifications for asphalt pavements in the state of arizona, which was initiated in 1999. Darwin task force current software status development of darwinme. It was noticed that progress of master curve development was stopped at the 30%. Transportation research board, national cooperative research program. Aashtoware pavement me design it is built upon the nchrp mechanisticempirical pavement design guide and expands and improves the features of the accompanying prototype computational software. Research results digest 290 the national academies press. Development of the 2002 guide for the design of new and rehabilitated. National cooperative highway research program nchrp. Aashto guide for design of pavement structures or one of its predecessors.
Guidelines for implementing nchrp 7a me design procedures in ohio. Development of the 2002 guide for the design of new and. Future plans for aashto me pavement design software linda pierce, chair aashto darwin task force january, 2008. The normalized axle load distributions by axle type for each truck. These models have been calibrated using many laboratory and field data and are routinely used by researchers and pavement engineers. Pccp models for rehabilitation and reconstruction decisionmaking by jianhua li research assistant stephen t. Preloaded software on the included laptop computer. Sep 27, 20 researchers are now incorporating the latest advances in pavement design into the new mechanisticempirical pavement design guide mepdg, developed under the national cooperative highway research program nchrp 1 37a project and adopted and published by aashto.
The guide includes procedures for the analysis and design of new. The objective of nchrp 7a is to develop a pavement design tool based on mechanisticempirical. Empirical pavement design guide mepdg developed under nchrp project 1 37a uses dynamic modulus to characterize. Comprehensive pavement design procedure structural analysis software available at. Guidelines for implementing nchrp 1 37a me design procedures in ohio. These specifications were to be based upon the mechanisticempirical pavement design guide me pdg developed for the national cooperative highway research program nchrp project 1 37a. The end products of these research efforts are the development of a mechanistic empirical pavement design guide mepdg and the accompanying software. The subgrade, base, and subbase resilient moduli values are the direct inputs in the nchrp 1 37a design methodology. Using only maximum stress in the fatigue transfer functions yielded a more finite number of critical damage locations that agree well with the nchrp 7a design software. California efforts towards mechanisticempirical pavement. Pccp models for rehabilitation and reconstruction decision. However, it is substantially more complex than the 1993 aashto design guide and it requires.
Rp 181 development and evaluation of performance tests to enhance superpave. Development of performance related specifications for asphalt pavements in the state of. The products developed under nchrp 7a have provided advancements in pavement design practices and work is continuing under nchrp, fhwa and various state agencies. The development of the mechanisticempirical pavement design guide mepdg under national cooperative highway research program nchrp projects 1 37a and 1 40d has significantly improved the ability of pavement designers to model and simulate the effects of the combination of traffic and. Accurate determination of critical structure responses plays a vital role in the ability of the mechanisticempirical pavement design guide mepdg to achieve a reliable pavement design.
Calibrating the mechanisticempirical pavement design guide. Recommended mechanisticempirical pavement design guide and software. The online version of the mechanisticempirical pavement design guide is available to anyone with internet access who has an interest in evaluating the guide and software. Coordinate technical activities with other relevant nchrp and fhwa projects, including nchrp projects 1 37a, 916, 917, 918, and 920. Directors, nchrp initiated project 1 37a to develop a guide for the design of new and rehabilitated pavement structures. This site will provide progress reports as well as links to other merelated resources. Freeware, available through transportation research board until 2012. The mepdg procedure offers several dramatic improvements over the current pavement design guide and. This proposal lead to the initiation of nchrp project 1 37, development of the 2002 guide for the design of new and rehabilitated pavement structures, and subsequently, nchrp project 1 37a, guide for the design of new and rehabilitated pavement structures, and nchrp project 1 40, facilitating the implementation of the guide for the design of.
Guide for mechanisticempirical design of new and rehabilitated pavement structures nchrp 1 37a march 30, 2004 the overall objective of the guide for the mechanisticempirical design of new and rehabilitated pavement structures referred to hereinafter as the design guide is to provide the highway community with a stateofthepractice. Design perfor mance values can be compared with threshold values, or comparisons of per july 2004 national cooperative highway research program recommended mechanisticempirical pavement design guide and software. Aashto guide development aashto joint task force on pavements jtf nchrp 1 37a. Nchrp 1 37a models proved to be more suitable for wsdot conditions. Available for evaluation this digest announces the availability of key products from nchrp project 7a, a development of the. Implementation of the nchrp 1 37a design guide final report volume 1. The texas department of transportation txdot used the recently released nchrp 1 37a guide and software to develop a strategic plan for its implementation of operations. Fhwa nhi05037 federal highway administration may 2006 nhi course no. Select software development contractor begin development 1518 month development cycle.
The end products of these research efforts are the development of a mechanisticempirical pavement design guide mepdg and the accompanying software. Highway administration, aashto, or the individual states participating in the national cooperative highway research program. This digest announces the availability of key products from nchrp project 1 37a, development of the 2002 guide for the design of new and rehabilitated pavement structures. Pccp models for rehabilitation and reconstruction decisionmaking. The methods developed in this project, while compatible with the nchrp 1 37a design guide, are. The sensitivity evaluation has already been conducted for new rigid jointed, and is currently in development for continuously reinforced pavements and new flexible pavements.
Nchrp 1 37a model binder input level 3 nchrp 1 40d model binder input level 3 29 evaluation of the mepdg dynamic modulus prediction models for. Data collection, processing, analysis and evaluation of pavements using ltpp database for 23 pavement sections located in seven different states. Nchrp project 7 will initiate the process of developing the 2002 guide. The results suggest that the default design criteria incorporated in the nchrp project 1 37a software are broadly consistent with what would be observed historically from pavements designed with. The mechanisticempirical approach at the heart of the nchrp 7a methodology. Appendix d nhi05037 federal highway administration.
A global sensitivity analysis samples the entire input parameter space of selected input variables. The design guide developed under national cooperative highway research program nchrp 7a project is a very complex pavement. Nchrp and the guide nchrp responds to state dots research needs as identified by the dots and aashto committees. Further work to develop the 2002 guide will be performed under project 1 37a. Development of design methods for geosynthetic reinforced. Ncat report 14 04 flexible pavement design state of the practice. This distribution of the mepdg developed in nchrp project 7a is made in the. In 2004, nchrp 1 37a was completed and delivered a mechanisticempirical pavement design guide and accompanying software. To improve the design and performance of roadway pavements, ara, in collaboration with our industry and university teaming partners, developed the mechanisticempirical pavement design guide mepdg methodology and software as part of national cooperative highway research program nchrp project 1 37a. This version will expire when the guide and software are available from. Nchrp s novel coronavirus disease covid19 response. These samples are used to create a matrix of design scenarios which were then be run through the nchrp 1 37a design software, to predict pavement performance. Project 1 37 was the initial step in the process of developing the 2002 guide. Further improvements to the mepdg were made as part of nchrp 1.