Transcription

GUIDEQuality Control for Concrete Paving:A Tool for Agency and IndustryDECEMBER 2021

About the CP Tech CenterThe mission of the National Concrete PavementTechnology Center (CP Tech Center) at Iowa StateUniversity is to unite key transportation stakeholdersaround the central goal of advancing concrete pavementtechnology through research, technology transfer, andtechnology implementation.NoticeThis document is disseminated under the sponsorshipof the U.S. Department of Transportation in theinterest of information exchange under CooperativeAgreement 693JJ31950004, Advancing ConcretePavement Technology Solutions. The U.S. Governmentassumes no liability for the use of the informationcontained in this document.The U.S. Government does not endorse productsor manufacturers. Trademarks or manufacturers’names appear in this material only because they areconsidered essential to the objective of the document.They are included for informational purposes only andare not intended to reflect a preference, approval, orendorsement of any one product or entity.Nonbinding ContentsIowa State UniversityNondiscrimination StatementIowa State University does not discriminate on the basisof race, color, age, ethnicity, religion, national origin,pregnancy, sexual orientation, gender identity, geneticinformation, sex, marital status, disability, or status asa US veteran. Inquiries regarding nondiscriminationpolicies may be directed to the Office of EqualOpportunity, 3410 Beardshear Hall, 515 Morrill Road,Ames, Iowa 50011, telephone: 515-294-7612, hotline:515-294-1222, email: [email protected] This GuideThis guide is a product of the National ConcretePavement Technology Center (CP Tech Center) atIowa State University, with funding from the FederalHighway Administration (FHWA). Complementarypublications developed by the CP Tech Center includeIntegrated Materials and Construction Practices (IMCP)for Concrete Pavement: A State-of-the-Practice Manual(2019), Guide to Concrete Overlays (2021), andConcrete Pavement Preservation Guide (new editionforthcoming). These and other publications related toconcrete paving are available on the CP Tech Center’swebsite, https://cptechcenter.org/.The contents of this document do not have the forceand effect of law and are not meant to bind the publicin any way. This document is intended only to provideclarity to the public regarding existing requirementsunder the law or agency policies. However, compliancewith applicable statutes or regulations cited in thisdocument is required.Reference Information for this GuideQuality Assurance StatementNational Concrete Pavement Technology CenterIowa State University Research Park2711 S. Loop Drive, Suite 4700Ames, IA 50010-8664515-294-5798https://cptechcenter.org/The Federal Highway Administration (FHWA) provideshigh-quality information to serve Government, industry,and the public in a manner that promotes publicunderstanding. Standards and policies are used toensure and maximize the quality, objectivity, utility, andintegrity of its information. FHWA periodically reviewsquality issues and adjusts its programs and processes toensure continuous quality improvement.Cavalline, T. L., G. J. Fick, and A. Innis. 2021. QualityControl for Concrete Paving: A Tool for Agency andIndustry. National Concrete Pavement TechnologyCenter, Ames, IA.For More InformationCover Image CreditsTop and Bottom: The Transtec Group, Inc., used with permissionCenter: University of North Carolina at Charlotte, used with permission

Technical Report Documentation Page1. Report No.2. Government Accession No.3. Recipient’s Catalog No.4. Title and Subtitle5. Report DateQuality Control for Concrete Paving: A Tool for Agency and IndustryDecember 20216. Performing Organization Code7. Author(s)8. Performing Organization Report No.Tara L. Cavalline, Gary J. Fick, and Al Innis9. Performing Organization Name and Address10. Work Unit No.National Concrete Pavement Technology CenterIowa State University2711 South Loop Drive, Suite 4700Ames, IA 50010-866411. Contract or Grant No.12. Sponsoring Organization Name and Address13. Type of Report and Period CoveredFederal Highway Administration1200 New Jersey Avenue, SEWashington, DC 2059014. Sponsoring Agency CodePart of Cooperative Agreement 693JJ31950004,Advancing Concrete Pavement Technology SolutionsGuide15. Supplementary NotesVisit https://cptechcenter.org for color pdfs of this and other research publications.16. AbstractQuality control (QC) by contractors, concrete suppliers, and materials suppliers is an integral component of a transportationagency’s quality assurance (QA) program and supports the construction of quality concrete infrastructure.This guide is intended to serve as a tool that both contractor and agency personnel can use at the batch plant, behind the paver,and at other locations on the job. Contractors can use this guide to improve or enhance their existing QC programs and plans byincorporating the appropriate provisions into their operations. This guide can also help agency personnel become familiar withthe components of a comprehensive QC plan for concrete paving projects, the ways such a QC plan benefits agencies, and waysto appropriately incorporate QC requirements into specifications. In addition, this guide provides background knowledge to helpagency and contractor personnel understand the elements of an agency’s QA program and why QC is an important part of thatprogram.Topics discussed include common agency QC requirements; the appropriate tools, processes, and procedures to meet theserequirements; continuous improvement activities; and the benefits for contractors of good quality control, including higherefficiency and productivity, increased profit, and safer operations.The material in this guide is presented in a manner that gives contractors the flexibility to develop their QC plans in a way thataccommodates their processes and procedures while providing a high likelihood of meeting agency requirements.17. Key Words18. Distribution Statementagency requirements—concrete infrastructure—quality assurance—quality controlNo restrictions.19. Security Classification(of this report)20. Security Classification(of this page)21. No. of Pages22. PriceUnclassified.Unclassified.165NAForm DOT F 1700.7 (8-72)Reproduction of completed page authorized

Quality Control for Concrete Paving:A Tool for Agency and IndustryDecember 2021AuthorsTara L. Cavalline, PhD, PE, University of North Carolina at CharlotteGary J. Fick, The Transtec Group, Inc.Al Innis, ConsultantManaging EditorOksana GiesemanEditorPeter HunsingerGraphic Design, Layout, and ProductionAlicia HoermannA guide fromNational Concrete Pavement Technology CenterIowa State University2711 South Loop Drive, Suite 4700Ames, IA 50010-8664Phone: 515-294-5798 / Fax: 515-294-0467https://cptechcenter.org

AcknowledgmentsThe CP Tech Center gratefully acknowledges the generous financial support of the FHWA for the development ofthis guide. The CP Tech Center and the authors also wish to thank the following knowledgeable, experienced, anddedicated experts who served on the Technical Advisory Committee and contributed to the development of this guide: Rick Bradbury, PE, Maine Department ofTransportation Pete Capon, Rieth-Riley Construction Co., Inc. Todd Hanson, PE, Iowa Department of Transportation Craig Hughes, Cedar Valley Corp., LLC Hugh Luedtke, Ajax Paving Industries, Inc. Maria Masten, PE, Minnesota Department ofTransportation Kevin McMullen, PE, Wisconsin ConcretePavement Association Dan Miller, PE, Ohio Department of Transportation Gary Mitchell, PE, American Concrete PavementAssociation John Privrat, PE, Duit Construction Co., Inc. John Staton, PE, Michigan Department ofTransportation Paul Tennis, Portland Cement AssociationThe authors would also like to thank the followingindividuals for their input and support throughout thedevelopment of this guide: John Adam, PE, National Concrete PavementTechnology Center Gina Ahlstrom, PE, Federal Highway Administration Jagan Gudimettla, PE, Federal Highway Administration Mike Praul, PE, Federal Highway Administration Sharon Prochnow, National Concrete PavementTechnology Center Gordon Smith, PE, National Concrete PavementTechnology Center Peter Taylor, PE, National Concrete PavementTechnology Center Steve Tritsch, PE, National Concrete PavementTechnology Center Sam Tyson, PE, Federal Highway Administration Leif Wathne, PE, American Concrete PavementAssociation Cindy Williams, Illinois TollwayAbbreviationsAARalkali-aggregate reactivityNRMCANational Ready Mixed Concrete AssociationAASHTOAmerican Association of State Highwayand Transportation OfficialsPEMperformance-engineered mixturesPWLACIAmerican Concrete Institutepercent within limitsQAACPAAmerican Concrete Pavement Associationquality assuranceQCASRalkali-silica reactivityquality controlSAIASTMAmerican Society for Testing and Materialsslag activity indexSAMCRCPcontinuously reinforced concrete pavementSuper Air MeterSCMFHWAFederal Highway Administrationsupplementary cementitious materialTRBGGBFSground granulated blast furnace slagTransportation Research BoardVKellyIAindependent assurancevibrating Kelly ballw/cmLOIloss on ignitionwater-to-cementitious materialsWRANETTCPNorthEast Transportation Training andCertification Programwater-reducing admixtureivQuality Control for Concrete Paving: A Tool for Agency and Industry

ContentsChapter 1Introduction Overview of This Guide 12Definitions 4Elements of a Quality Assurance Program 5Message to Agencies 6Message to Contractors 7Chapter 2Quality Control Fundamentals Introduction to Quality Control 910Organizational-Level Quality Management 11Communication 12Quality Control Plans 13Understanding Variability Recommended Approach for Contractor QualityControl 36Implementing Quality Control 38Chapter 5Quality Control for Concrete PavementConstruction Implementation of Quality Control for ConcretePavement Construction 3940Prepaving 43Subgrade/Subbase 43Staking and Stringline or Stringless Paving 44Fine Grading 45Dowel Basket Placement 4715Steel Placement for Continuously ReinforcedConcrete Pavement 48Types and Sources of Variability 15Paver Preparation 50Variability and Process Control 17Plant Site and Mixture Production 5219Equipment and Laboratories 52Personnel 54Materials 54Sampling and Statistical Process Control Chapter 3Quality Control for Materials Suppliers Portland Cement and Blended Cement 2324Supplementary Cementitious Materials 27Slag Cement 27Fly Ash 27Natural Pozzolans 28Chemical Admixtures 28Aggregates 28Summary and Additional Resources 29Chapter 4Performance-Engineered Concrete Mixtures 31Summary of Performance-Engineered MixtureRequirements 33Concrete Strength 33Susceptibility to Slab Warping and Cracking Due toShrinkage 33Freeze-Thaw Durability 33Transport Properties 33Aggregate Stability 34Workability 34Cement and Cementitious Materials 54Aggregates 55Steel Reinforcement, Dowels, and Other EmbeddedItems 56Mixture Design (Prequalification) 56Mixture Verification (Field Setup and Trial Batches) 58Mixture Production 59Placement, Finishing, Texturing, Curing, and Sawing 63Transportation and Spreading of Concrete 63Slipforming (Extrusion) 64Insertion of Dowels and/or Tie Bars 65Hand Finishing 66Texturing 67Curing 68Sawing 69Temperature and Weather Adjustments 70Smoothness Quality Control for Concrete Paving: A Tool for Agency and Industry70v

Acceptance 71Appendix BExample Quality Control Plan Provisions Aggregate Stockpile Management 107108Testing of Concrete for Compressive Strength 108Acceptance Tests for Concrete Mixtures 71Acceptance Tests for Concrete Pavement 71Acceptance and the Percent Within LimitsApproach 72Preplaced Dowel Baskets 10873Inspection of Underlying Materials before Paving 109Concrete Placement and Consolidation 109Curing 109Corrective Actions Chapter 6Tools for Quality Control Process Diagrams, Check Sheets, and Other Tools 7576Run Charts and Control Charts 81Constructing Run Charts and Control Charts 82Example Control Chart: Central Line and LimitsEstablished Using Statistical Methods 85Example Run Chart: Central Line and LimitsEstablished Using Nonstatistical (Specification-Based)Targets 86Observing and Understanding Trends in Run Chartsand Control Charts 87Using Two Measurements on a Run Chart or aControl Chart 90Using Run Chart and Control Chart Data toImprove Processes 92Appendix CQuality Control Plan Outline 111Sections 1 and 2: General Quality Control Informationand Applicable Specifications and Standards 112Overview 112Outline for Sections 1 and 2 112Sections 3 through 6: Concrete Mixture Production andConcrete Paving Process 112Overview 112Typical Content for Each Step 112Example Content for Step 5.2.4 113Outline for Sections 3 through 6 114Appendix DModel Quality Control Plan 117Appendix EControl Charts: Additional StatisticalExample Data Used in the Example 145146100Constructing the Control Charts 148AASHTO 100Refining the Control Charts 152ASTM 102Using Control Charts Effectively 155Additional Resources 155Records Management 93Chapter 7Closing 95References Works Cited 9797Standards and Specifications Appendix AReview of Agency Quality ControlRequirements General Quality Control Requirements 103104Quality Control Requirements for Concrete MixtureComponents 105Quality Control Requirements for Concrete Mixtures 105Quality Control Requirements for Batching and Testingof Concrete 105Quality Control Requirements for ConcretePlacement vi106Quality Control for Concrete Paving: A Tool for Agency and Industry

FiguresChapter 1Figure 1.1. Benefits of improved quality fortransportation facilities 2Figure 1.2. Core elements of a quality assuranceprogram 5Chapter 2Figure 2.1. Plan-do-check-act cycle 10Figure 2.2. FHWA quality control flowchart 15Figure 2.3. Sources of construction variability 16Figure 2.4. Variation observed in subgroups sampledfrom an in-control process experiencing only chancecause (natural) variability 18Figure 2.5. Variation in subgroups sampled from anout-of-control process experiencing assignable cause(not natural) variability 18Figure 2.6. Random sampling 20Figure 5.3. Proof rolling of recycled base material 43Figure 5.4. Stringline and paving hub alignment 44Figure 5.5. Stringless paving system guidance usingtotal stations 45Figure 5.6. Dowel basket anchored to subgrade (top)and existing asphalt (bottom) 47Figure 5.7. Preplaced dowel baskets fastened toasphalt base, with markings located on base to guidesawcutting 47Figure 5.8. Verification of positioning of reinforcing barsfor CRCP and support conditions (left) and staking ofreinforcing bars to subgrade (right) 49Figure 5.9. Layout of a concrete batching plant 53Figure 5.10. Aggregate stockpiles 55Figure 5.11. Tarantula curve analysis 58Figure 5.12. Maturity meter (left) and sensor (right) 58Figure 2.7. Biased/selective sampling (in this example,by time order) 20Figure 5.13. Microwave test to determine w/cm ratioof mixture in the field 58Chapter 3Figure 3.1. Cement plant in Missouri that produces 4million tons annually and supplies 23 states 24Figure 5.15. Uniform deposition of concrete in frontof the paver 64Figure 3.2. Typical mill certificate for portland cement 25Figure 3.3. ASTM C917 report showing cementvariability during a certain production period Figure 5.14. Maturity testing of concrete pavement 61Figure 5.16. Maintenance truck (at left) with tools andequipment available to address issues with the paverduring paving 6426Figure 5.17. Paver equipped with dowel bar insertertechnology 65Chapter 4Figure 4.1. AASHTO T 334 cracking tendency test 35Figure 5.18. Preplaced tie bars supported and fastenedto the grade 66Figure 4.2. AASHTO TP 118 Super Air Meter (SAM) 35Figure 5.19. Verification of dowel bar location byprobing behind the paver 66Figure 5.20. Hand finishing 66Figure 5.21. Texturing machine 67Figure 5.22. Longitudinal tining 67Figure 5.23. Curing machine applying curingcompound 68Figure 5.24. Screenshot of HIPERPAV softwareshowing cracking risk at different times of day 69Figure 4.3. AASHTO TP 119 bulk resistivity test 35Figure 4.4. AASHTO T 358 surface resistivity test 35Figure 4.5. AASHTO TP 129 VKelly test 35Figure 4.6. Box Test 36Figure 4.7. Example of PEM implementation andproject flow 37Figure 4.8. Example of construction factors affectingw/cm ratio and PEM properties 38Chapter 5Figure 5.1. Four stages of QC for portland cementconcrete paving that should be included in a QC plan 40Figure 5.2. Intelligent compaction used on subgrade 43Figure 5.25. Real-time smoothness measurement devicemounted to the back of a paver 71Figure 5.26. SAM testing at the paver 71Figure 5.27. MIT SCAN-T3 72Figure 5.28. MIT-DOWEL-SCAN 72Quality Control for Concrete Paving: A Tool for Agency and Industryvii

Chapter 6Figure 6.1. Flowchart showing process for preparing andtesting trial batches of concrete using the Box Test 77Figure 6.2. Check sheet for inspection of aggregate basecourse prior to paving 78Figure 6.3. Data sheet showing compressive strengthmeasurements 79Figure 6.4. Paper materials ticket 80Figure 6.5. E-ticketing system for concrete materials 80Figure 6.6. Run chart for the flexural strength of aconcrete mixture 81Figure 6.7. Typical central line (process average) andlimits on a control chart 83Figure 6.8. Typical central line (target line or processaverage) and limits on a run chart, where statisticalmethods are not used to establish limits 84Figure 6.9. Control chart for concrete flexural strength,with central line and control limits established usingstatistical methods 85Figure 6.10. Run chart for air content in fresh concrete,with control limits established using specification limits 87Chapter 7Figure 7.1. Impact of continuous improvements in QCon costs 95Appendix CFigure C.1. Burlap drag behind the paver Appendix EFigure E.1. X– chart of 7-day compressive strength testresults, showing subgroup averages plotted over time 148Figure E.2. R-chart of 7-day compressive strength testresults, showing subgroup ranges plotted over time 148Figure E.3. X– chart with trial central line and controllimits and control limits 154Figure E.6. R-chart with trial and revised central linesand control limits 154Figure 6.12. Assignable cause variability suggested by nineconsecutive test results on one side of the central line 88Figure 6.13. Assignable cause variability suggested by 14test results alternating above and below the central line(acting as two populations) 8989Figure 6.15. Assignable cause variability suggested byfour of five test results on the same side of the centralline that are more than one standard deviation from thecentral line 89Figure 6.16. Assignable cause variability suggested by15 test results within one standard deviation from thecentral line 89Figure 6.17. Assignable cause variability suggested byeight consecutive test results more than one standarddeviation from the central line 89Figure 6.18. Run chart for air content and unit weight 90Figure 6.19. Run chart for air content and unit weight,with secondary y-axis inverted 90Figure 6.20. Relationship between design air contentand design unit weight and between design values andmeasured values 91Figure 6.21. Control chart for compressive strength andsurface resistivity 92viii151Figure E.4. R-chart with trial central line and controllimits 151–Figure E.5. X chart with trial and revised central linesFigure 6.11. Assignable cause variability suggested bysix consecutive test results increasing or decreasing 88Figure 6.14. Assignable cause variability suggestedby two of three test results more than two standarddeviations from the central line 113Quality Control for Concrete Paving: A Tool for Agency and Industry

TablesChapter 2Table 2.1. Examples of testing precision Table 5.16. Concrete mixture QC tests 19Chapter 4Table 4.1. PEM properties and test methods 34Chapter 5Table 5.1. Example framework for project-level QCactivities 42Table 5.2. Subgrade QC—inspection items, QCmeasurements, and checklists 44Table 5.3. Subbase QC—inspection items, QCmeasurements, and checklists 45Table 5.4. Staking and stringline or stringless pavingQC—inspection items, QC measurements, andchecklists 46Table 5.5 Fine grading QC—inspection items, QCmeasurements, and checklists 46Table 5.6. Dowel basket QC—inspection items, QCmeasurements, and checklists 48Table 5.7. CRCP reinforcing steel QC—inspectionitems, QC measurements, and checklists 61Table 5.17. Example QC sampling and testing table 62Table 5.18. Transportation of concrete QC—inspectionitems, QC measurements, and checklists 63Table 5.19. Spreading of concrete QC—inspectionitems, QC measurements, and checklists 64Table 5.20. Slipforming of concrete QC—inspectionitems, QC measurements, and checklists 65Table 5.21. Insertion of dowels and tie bars QC—inspection items, QC measurements, and checklists 66Table 5.22. Hand finishing QC—inspection items,QC measurements, and checklists 67Table 5.23. Texturing QC—inspection items, QCmeasurements, and checklists 68Table 5.24. Curing QC—inspection items, QCmeasurements, and checklists 68Table 5.25. Sawing QC—inspection items, QCmeasurements, and checklists 69Table 5.26. Factors influencing pavement smoothness thatshould be considered in development of a QC plan 70Table 5.27. Mixture acceptance tests 71Table 5.8. Paver preparation QC—inspection items,QC measurements, and checklists 50Table 5.28. Construction QC and acceptance tests 72Table 5.9. Plant setup and calibration QC—inspectionitems, QC measurements, and checklists 53Chapter 6Table 6.1. Measurements of concrete flexural strength 85Table 5.10. Aggregate stockpile QC—inspection items,QC measurements, and checklists 56Table 6.2. Design values of unit weight at selecteddesign air contents 91Table 5.11. Recommended laboratory tests duringprequalification of a mixture 57Table 6.3. Example comparison of measured anddesign values for unit weight and air content 91Table 5.12. Example sieve analysis results 58Table 5.13. Field setup tests 5949Table 5.14. Required batch tolerances for ready-mixedconcrete 60Table 5.15. Mixture production QC—inspection items,QC measurements, and checklists 60Appendix ETable E.1. Seven-day compressive strength test resultsused to support control chart development 147Table E.2. Factors for computing central lines and–control limits for X charts, S charts, and R-charts Quality Control for Concrete Paving: A Tool for Agency and Industry150ix

xQuality Control for Concrete Paving: A Tool for Agency and Industry

Chapter 1IntroductionOverview of This Guide2Definitions4Elements of a Quality Assurance Program5Message to Agencies6Message to Contractors7Chapter 1. Introduction1

Quality control (QC) by contractors, concrete suppliers,and materials suppliers is an integral componentof a transportation agency’s quality assurance (QA)program and supports the construction of qualityconcrete infrastructure. QC encompasses the personnel,equipment, and practices required to control thequality of the product(s) being produced and workbeing performed. Central to QC are organizationallevel quality management programs and project-levelQC plans. Jointly, these activities and processes ensurethat the appropriate elements of QC are implementedto meet the quality requirements or standards for theproduct(s) produced and work performed.as part of the Federal Highway Administration’s(FHWA’s) PEM initiative. In contrast to mixturesbased on prescriptive specifications, PEMs (discussedin Chapter 4 of this document) allow contractors andsuppliers to use their knowledge to produce betterquality concrete. As agencies implement performancetype specification provisions, contractor QC programsand plans will become an increasingly importantcomponent of project QA. During the transition toperformance specifications, many of the prescriptivecontractual requirements and responsibilities related toquality will be transferred to the contractor, along withsome of the performance risks.At the project level, the implementation of acomprehensive QC plan provides confidence to agenciesand other stakeholders that when the plan is followed,specification provisions will be met. The benefits ofa QC plan are not limited to agencies, however. Awell-implemented QC plan provides many benefits tocontractors, including increased profitability, reducedrework, greater pay factors, improved public image andcustomer satisfaction, and, in some cases, improvedsafety (Figure 1.1). Contractors can achieve thesebenefits through incorporating appropriate provisionsinto their operations and QC plans.Due to the unique nature of highway construction, themeasures that need to be taken to ensure quality differfor each project. Contract documents (including plans,specifications, and special provisions) define the qualitystandards that an agency expects. However, it is up tocontractors to specify the means and methods necessaryto provide confidence that quality is attained by theirown personnel, equipment, and processes.Moreover, contractors that have instituted robustQC programs throughout their organizations will bebetter prepared for an upcoming shift in the highwayconstruction industry. In recent years, some agencieshave begun moving toward performance specificationsand performance-engineered concrete mixtures r qualitydisputesSafe andlong-lastingconcretepavementsReduced costsfor agency andcompetitiveadvantage forcontractorImprovedpublic imageAdapted from Fick et al. 2012Overview of This GuideThis document is intended to serve as a tool that can beused at the batch plant, behind the paver, and at otherlocations on the job. The primary target audience iscontractors desiring to improve or enhance their existingQC programs and plans; this document presentsthe means for contractors to achieve the benefits ofwell-implemented QC through incorporating theappropriate provisions into their operations. However,this document can also help agency personnel becomefamiliar with the components and approaches thatcomprise a comprehensive QC plan for concrete pavingprojects, the ways such a QC plan benefits an agency,and ways to appropriately incorporate QC requirementsinto specifications.In addition, this document provides backgroundknowledge to help agency and contractor personnelunderstand the elements of an agency’s QA programand why QC is an important part of that program.As part of the development of this document, the QCrequirements related to concrete paving for 15 agencieswere reviewed; a list of commonly and less commonlyspecified requirements is presented in Appendix A. Thereader should be mindful that agency QC requirementsare minimum requirements, and additional QC activitiesare very often needed to support the success of a project.Figure 1.1. Benefits of improved quality for transportationfacilities2Quality Control for Concrete Paving: A Tool for Agency and Industry

The QC guidance in this document is presented ina manner that provides flexibility for contractors todevelop their QC plans in a way that accommodatestheir own means and methods (frequently referred to as“processes and procedures” in the quality managementfield) while providing a high likelihood of meetingagency requirements.This document includes information necessary forcontractors to do the following: Understand common agency QC requirements Develop and implement the appropriate tools,processes, and procedures to meet agency QCrequirements Develop and implement continuous improvementactivities to more effectively and efficiently meetagency requirements Recognize that good quality control offers severalbenefits for contractors, including higher efficiencyand productivity, increased profit, and safer operationsThe material presented in this document is outlined below.Chapter 2 presents a brief introduction to QC. Thechapter describes the components of an organizationallevel QC program that supports QC across operationsand projects. Because people are the foundation ofquality management, the chapter emphasizes theimportance of communication, with Appendix Bproviding example QC plan provisions that demonstrate“poor,” “fair,” and “good” language and level ofdetail. The chapter also introduces the fundamentalcomponents of QC plans and the topics of variability,sampling, and statistical process control.Because constructing quality concrete pavementsrequires materials that meet quality standards, Chapter3 describes QC for suppliers of concrete pavementmaterials, including cementitious materials, chemicaladmixtures, and aggregates. Readers seeking additionalinformation on this type of QC are referred to otherkey resources.Chapter 4 describes the characteristics of PEMs, thebenefits that can be achieved through the use of PEMsand associated tests, and QC processes and provisionsthat support PEMs. The move toward PEMs by manyagencies provides opportunities for contractors andsuppliers to more fully capitalize upon their knowledgeand experience to produce quality concrete pavements,but the use of PEMs often requires contractors toimplement an enhanced QC program.Chapter 5 presents QC methods for concrete pavementconstruction. The chapter describes the establishmentand implementation of a QC program that includesmixture design (prequalification), mixture verification(field setup), mixture and construction QC, andmixture and construction acceptance. QC provisions forconcrete batching and paving are then presented, with anemphasis on the measurements and observations requiredfor a successful paving project. Best practices to supportthe development of a QC plan are described throughoutthe chapter, along with guidance to help contractorsdistinguish between specified requirements and QCresponsibilities. An overview of typical acceptance testingapproaches and a brief discussion of corrective actionsclose the chapter. The guidanc

515-294-1222, email: [email protected] About This Guide This guide is a product of the National Concrete Pavement Technology Center (CP Tech Center) at Iowa State University, with funding from the Federal Highway Administration (FHWA). Complementary publications developed by the CP Tech Center include