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2020 N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M NCHRP RESEARCH REPORT 946 Procedures and Guidelines for Validating Contractor Test Data Adam J. T. Hand Mohamed A. Nimeri Elie Y. Hajj Peter E. Sebaaly University of nevada, reno Reno, NV Randy C. West Michael A. Heitzman Fan Yin national Center for asphalt teChnology (nCat), aUbUrn University Auburn, AL Charles S. Hughes ConsUltant Charlottesville, VA Shiraz Tayabji ConsUltant Columbia, MD Subscriber Categories Construction â¢ Materials Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state departments of transportation (DOTs) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transporta- tion results in increasingly complex problems of wide interest to high- way authorities. These problems are best studied through a coordinated program of cooperative research. Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 ini- tiated an objective national highway research program using modern scientific techniquesâthe National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration (FHWA), United States Department of Transportation, under Agree- ment No. 693JJ31950003. The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRBâs recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive com- mittee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, univer- sities, and industry; TRBâs relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of special- ists in highway transportation matters to bring the findings of research directly to those in a position to use them. The program is developed on the basis of research needs iden- tified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&Iâs recommendations are proposed to the AASHTO Board of Direc- tors and the National Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Academies and TRB. The needs for highway research are many, and NCHRP can make significant contributions to solving highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement, rather than to substitute for or duplicate, other highway research programs. Published research reports of the NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM are available from Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet by going to http://www.national-academies.org and then searching for TRB Printed in the United States of America NCHRP RESEARCH REPORT 946 Project 10-100 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-48144-1 Library of Congress Control Number 2020936546 Â© 2020 National Academy of Sciences. All rights reserved. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FTA, GHSA, NHTSA, or TDC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. NOTICE The research report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors. The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturersâ names appear herein solely because they are considered essential to the object of the report.
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. John L. Anderson is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to provide leadership in transportation improvements and innovation through trusted, timely, impartial, and evidence-based information exchange, research, and advice regarding all modes of transportation. The Boardâs varied activities annually engage about 8,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. Learn more about the Transportation Research Board at www.TRB.org.
C O O P E R A T I V E R E S E A R C H P R O G R A M S AUTHOR ACKNOWLEDGMENTS The research reported herein was performed under NCHRP Project 10-100, âProcedures and Guide- lines for Validating Contractor Test Data,â by the University of Nevada, Reno (UNR). National Center for Asphalt Technology (NCAT) served as subcontractor and Dr. Shiraz Tayabji and Mr. Charles Hughes served as consultants. Dr. Adam J. T. Hand of UNR was the principal investigator. CRP STAFF FOR NCHRP RESEARCH REPORT 946 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Amir N. Hanna, Senior Program Officer Eileen P. Delaney, Director of Publications Natalie Barnes, Associate Director of Publications NCHRP PROJECT 10-100 PANEL Field of Materials and ConstructionâArea of Specifications, Procedures, and Practices Lisa B. Zigmund, PRIME AE Group, Columbus, OH (Chair) (formerly with Ohio DOT) Richard L. Bradbury, Maine DOT, Scarborough, ME Eliana V. Carlson, Pennoni Associates, King of Prussia, PA (formerly with Connecticut DOT) Richard âRickâ Douds, Georgia DOT, Forest Park, GA Sharon D. Hawkins, Maryland State Highway Administration, Baltimore, MD Charles D. Suszko, Caltrans, Sacramento, CA Richard Duval, FHWA Liaison
This report reviews and evaluates the procedures and practices for validating contrac- tor test data used in the acceptance of construction materials. The report also proposes a related practice for incorporation into AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing. The information contained in the report will be of immediate interest to state materials and construction engineers and others involved in the different aspects of highway infrastructure construction and quality assurance. Many state departments of transportation (DOTs) utilize contractor test data in the acceptance process for construction materials. Federal regulation 23 CFR 637B permits the use of contractor test data for acceptance of construction materials, but it requires DOTs to validate the data with independent test results. A combination of hypothesis tests (specifically the F- and t-tests) is commonly used to determine if the contractor and DOT test results are from the same statistical population. However, other statistical approaches may provide a better means for evaluating contractor test data and address related issues. Research was needed to identify the procedures currently available for validating con- tractor test data and recommend procedures for use in validating contractor test data for construction materials and other applications. These procedures were to address the dif- ferent applications and related issues, such as sample size, minor deviations, and associated risks. Also, research was needed to prepare guidelines for the application of these procedures. Under NCHRP Project 10-100, âProcedures and Guidelines for Validating Contractor Test Data,â the research team led by the University of Nevada, Reno worked with the objec- tives of (1) recommending procedures for validating contractor test data for construction materials and (2) preparing related guidelines, in the form of a proposed standard prac- tice, for their application. To accomplish these objectives, the research team reviewed and evaluated the procedures and practices currently available for validating contractor test data used in the acceptance of construction materials. Based on the findings of this evalu- ation, the research team recommended a procedure that incorporates the F- and t-tests and prepared related guidelines, in the form of standard practice, for incorporation into AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing. The report also includes examples illustrating application of the proposed procedure. This report summarizes the work performed in the project and includes the proposed practice for validating contractor test data, examples illustrating use of the proposed prac- tice, and several appendices that provide further details on the different aspects of the research. These appendices, A through E, can be downloaded from www.trb.org by search- ing for âNCHRP Research Report 946.â F O R E W O R D By Amir N. Hanna Staff Officer Transportation Research Board
Note: Photographs, figures, and tables in this report may have been converted from color to grayscale for printing. The electronic version of the report (posted on the web at www.trb.org) retains the color versions. 1 Summary P A R T I Research Overview 5 Chapter 1 Background 5 1.1 Problem Statement 5 1.2 Objective and Organization of the Report 7 Chapter 2 Research Approach 7 2.1 Gathering Information 17 2.2 Numerical Simulations 19 2.3 SHA Data 27 Chapter 3 Findings and Applications 27 3.1 Numerical Simulation Findings 31 3.2 SHA Data Findings 34 3.3 Illustrative Examples 45 3.4 Case Study Example 49 Chapter 4 Summary and Recommendations for Future Research 51 References 54 Abbreviations and Symbols 55 Appendices AâE P A R T I I Proposed Practice for Validating Contractor Test Data 59 Section 1 Scope 60 Section 2 Referenced Documents 60 Section 3 Terminology 65 Section 4 Procedures and Guidelines for Validating Contractor Test Data 73 Annex A Recommended Sampling Plans 85 Annex B Procedure for Determining Statistical Outliers 89 Annex C Statistical Tables C O N T E N T S