Wisconsin Highway Research ProgramPerpetual PavementInstrumentationfor the MarquetteInterchange ProjectPhase 1SPR #0092-06-01Nicholas J Hornyak, James A CrovettiDavid E. Newman, Jay P. SchabelskiTransportation Research CenterMarquette UniversityAugust 2007WHRP 07-11

Marquette Interchange Perpetual Pavement InstrumentationProject: Phase I Final ReportPresented To:Wisconsin Highway Research ProgramSubmitted By:Transportation Research CenterDepartment of Civil and Environmental EngineeringMarquette UniversityP.O. Box 1881Milwaukee, Wisconsin 53201-1881August 15, 2007

Technical Report Documentation Page1. Report No.WHRP 07-112. Government AccessionNo3. Recipient’s Catalog No4. Title and SubtitlePerpetual Pavement Instrumentation for the Marquette InterchangeProject – Phase 1 Final Report5. Report DateSeptember 20076. Performing Organization CodeUniv. of Wisconsin - Madison7. AuthorsNicholas J. Hornyak, James A. Crovetti, David E. Newman,Jay P. Schabelski9. Performing Organization Name and AddressTransportation Research CenterMarquette University8. Performing Organization ReportNo.12. Sponsoring Agency Name and AddressWisconsin Department of TransportationDivision of Business ServicesResearch Coordination Section4802 Sheboygan Ave. Rm 104Madison, WI 5370713. Type of Report and PeriodCoveredFinal Report, 2005-200710. Work Unit No. (TRAIS)11. Contract or Grant No.WisDOT SPR# 0092-06-0114. Sponsoring Agency Code15. Supplementary Notes16. AbstractThis report provides details on the design, installation and monitoring of a pavement instrumentation system forthe analysis of load-induced stresses and strains within a perpetual HMA pavement system. The HMApavement was constructed as part of an urban highway improvement project in the City of Milwaukee,Wisconsin. The outer wheel path of the outside lane was instrumented with asphalt strain sensors, base andsubgrade pressure sensors, subgrade moisture and temperature sensors, HMA layer temperature sensors,traffic wander strips and a weigh in motion system. Environmental sensors for air temperature, wind speed andsolar radiation are also included. The system captures the pavement response from each axle loading andtransmits the data through a wireless link to a resident database at Marquette University. The collected data willbe used to estimate the fatigue life of the perpetual HMA pavement and to modify, as necessary, pavementdesign procedures used within the State of Wisconsin.17. Key WordsPerpetual pavement, asphalt strain, fatigue analysis,traffic wander pattern, weigh in motion,environmental sensors.19. Security Classif.(of this report)UnclassifiedForm DOT F 1700.7 (8-72)18. Distribution StatementNo restriction. This document is available to thepublic through theNational Technical Information Service5285 Port Royal RoadSpringfield VA 2216119. Security Classif. (of this page)Unclassified20. No. of PagesReproduction of completed page authorizedii21. Price

DisclaimerThis research was funded through the Wisconsin Highway ResearchProgram by the Wisconsin Department of Transportation and the FederalHighway Administration under Project # 0092-06-01. The contents of this reportreflect the views of the authors who are responsible for the facts and accuracy ofthe data presented herein. The contents do not necessarily reflect the officialviews of the Wisconsin Department of Transportation or the Federal HighwayAdministration at the time of publication.This document is disseminated under the sponsorship of the Departmentof Transportation in the interest of information exchange. The United StatesGovernment assumes no liability for its contents or use thereof. This report doesnot constitute a standard, specification or regulation.The United States Government does not endorse products ormanufacturers. Trade and manufacturers’ names appear in this report onlybecause they are considered essential to the object of the document.iii

AcknowledgementsThe authors wish to thank the Wisconsin DOT and North-Leg project contractorsfor their valuable cooperation during this research study. A special thanks goesto the following people for their assistance during the study:Wisconsin DOTLen MakowskiDeb SchwermanJudy RyanFrank RiveraPayne & DolanSigne RicheltTodd HughesBill EvenichWalsh ConstructionNick FaulCollins EngineersFrank HinesTom CollinsOutdoor LightingGary DlugopolskiTony NedomaHNTBPaul KutzTAPCOBrian ScharlesBob Lingnofskiiv

Executive SummaryProject SummaryThe first phase of this project was focused on developing and implementing aninstrumentation plan for a section of a hot mix asphalt (HMA) perpetual pavementlocated within the north leg of the Marquette Interchange project. The mainobjectives of this project as a whole are to instrument a pavement to acquire thenecessary data to provide information necessary for a comprehensivemechanistic-empirical pavement appraisal. The information generated from thisproject will help calibrate certain design factors to account for local conditions.BackgroundPavement design practices have relied on concepts generated years ago in testsconducted by AASHTO and other agencies. These design practices arecurrently being transitioned from the largely empirical based design methods tothose that are based heavily on mechanics of materials with some empiricalelements still residing within. This transition in design practices requires carefulconsideration of the variables which are sensitive to location, traffic patterns, andenvironment of the regional area.In April 2005 a proposal to instrument a HMA perpetual pavement wassubmitted to the Wisconsin Highway Research Program and subsequentlyawarded to the Transportation Research Center at Marquette University.v

ProcessThis specific phase of the project was carried out in multiple tasks. A detailedimplementation plan was generated to supplement the general plan laid out inthe original proposal. Within this detailed plan, specific brands and models ofsensors were selected based upon detailed literature reviews, directcommunication with members of the engineering community, and also throughsome experimental procedures. This process helped to develop a list of theequipment that was best suited for the job and budget. Alternative equipmentplans were also developed to suit any changes in design of the MarquetteInterchange project that may have occurred over the duration before installation.The proposed sensor list included asphalt strain gauges, earth pressure cells,moisture probes, temperature sensors, a wheel wander grid, a weigh-in-motionsystem, various environmental sensors, and data collection/transmission/storagedevices.Another important aspect the project was the proposed location of the testsection. The test section needed to provide clear traffic flow with little weavingand other interruptions while still acting as a representative segment ofpavement. The location also needed to provide for other needs such aselectrical power and accessibility.Once the detailed implementation plan was generated and approved, theinstallation procedures needed to integrated into the scheduling requirements ofthe other construction activities on the north leg project. This requiredcommunicating with the various construction contractors to make those involvedvi

on the construction project aware of activities of this research project. Theproject was closely monitored and frequently visited so the installation of theequipment could go as planned without disrupting the activities of the otherconstruction crews. Additionally it was important to monitor construction crewsand inform them as needed to protect the sensitive equipment from damage.The physical installation of the sensors in the pavement structure was avery critical step in the whole project. The dynamic pavement sensors (asphaltstrain gauges, earth pressure cells, etc.) are the main focus of the research, anda large number of sensors not surviving the installation could have compromisedthe entire project. Engineering ingenuity and careful practices, taking note tofollow manufacturers’ warnings and recommendations when available, were usedto ensure a good sensor survival rate.A great deal of time was also spent setting up the equipment used to readthe numerous sensors. This included careful calibration of many sensors used inthe project and also the software needed to read, monitor, and manage thesystem.FindingsBecause of the careful planning and cooperation with the contractors theinstallation of the pavement sensors was a success. Immediately after paving,only one strain sensor was not responding completely while another wasproducing an excessively noisy signal, but still operational. All other straingauges and earth pressure cells were operational. Up to the time of thepublication of this report, data collection is underway of the traffic data and beingvii

stored on the project database. The second phase of this project, which is inprogress, will provide the necessary means of data distribution and data analysis.RecommendationsWhile no explicit recommendations regarding expected perpetual pavementperformance are yet available, this research is expected to provide theengineering community with a wealth of high quality data that is the mostcomplete and thorough set known to exist at this time. Implicit recommendationscan found throughout this report from the proper selection of sensors, testsection location, and overall guidelines for the implementation of other suchprojects that may be similar in part, or in whole, to this project. It is hoped thatthis report can make itself useful for others doing similar work in the future.viii

Table of ContentsChapter 1 - Literature Review . 11.1 MnROAD Study. 11.2 NCAT . 3Chapter 2 - Field Instrumentation Plan . 52.1 Problem Statement . 52.2 Instrumentation Location . 62.3 Asphalt Strain. 72.4 Subgrade and Base Course Pressure. 122.5 Subgrade Moisture . 132.6 HMA Layer Temperature. 142.7 Weather Conditions. 142.8 Axle Load Spectra. 152.9 Wheel Wander . 172.10 Data Recordation . 182.11 Remote Monitoring . 192.12 Field Installations . 202.13 Cost Estimate. 22Chapter 3 - Field Installations . 243.1 Pre-Installation Sensor Tests . 243.1.1 Asphalt Strain Gauges. 253.1.2 Geokon Model 3500 Earth Pressure Cell . 493.1.3 Decagon Devices Inc. ECH2O EC-5 Soil Moisture Probe. 53ix

Table of Contents (Cont.)3.2 Instrument Installation . 593.2.1 Sub-Grade Instruments . 593.2.2 Base Layer Earth Pressure Cell . 653.2.3 Asphalt Strain Gauges. 663.2.4 Inductance Loop Detector . 723.2.5 Equipment Cabinet . 763.2.6 Wireless Antenna . 783.2.7 Pavement Temperature Gradient Probe. 793.2.8 Wheel Wander and Weigh-in-Motion System . 833.2.9 Testing Procedures . 983.2.10 Infrastructure . 1053.2.11 Miscellaneous Project Activities. 114Chapter 4 - System Demonstration. 1194.1 System Demonstration . 1194.2 Database. 1194.3 Data Viewer. 1224.4 Phase II Work Plan . 125Appendix A – Strain Gauge Calibration Data.A-1x

List of FiguresFigure 2-1Figure 2-2Figure 3-1Figure 3-2Figure 3-3Figure 3-4Figure 3-5Figure 3-6Figure 3-7Figure 3-8Figure 3-9Figure 3-10Figure 3-11Figure 3-12Figure 3-13Figure 3-14Figure 3-15Figure 3-16Figure 3-17Figure 3-18Figure 3-19Figure 3-20Figure 3-21Figure 3-22Figure 3-23Figure 3-24Figure 3-25Figure 3-26Figure 3-27Figure 3-28Figure 3-29Figure 3-30Figure 3-31Figure 3-32Figure 3-33Figure 3-34Figure 3-35Figure 3-36Figure 3-37Figure 3-38Figure 3-39Figure 4-1Figure 4-2Figure 4-3Sensor layout . 11WIM and wheel wander layouts. 17Bonded electrical resistance strain gauge . 28Wheatstone bridge circuit . 29Full bridge circuit diagram . 31Example of calibration data for CTL gauge . 38Dynamic response of CTL gauge . 42Setup for Dynatest gauge calibration. 46Geokon model 3500 and Decagon EC-5. 50Geokon calibration data. 53Soil moisture probe calibration data . 58Layout of sensor placed in native soil layer . 62Installation of native soil layer earth pressure cell . 64Steps for installing earth pressure cell. 66Strain sensor spacing and dimension. 68Final configuration of strain sensors . 69Marking and placing strain sensors for installation . 70Placing screened asphalt on strain sensors . 71Final placement of WIM and wheel wander sensors . 73Loop installation steps . 75Equipment cabinet. 78Wireless antenna and transmission path. 79Pavement temperature gradient probe . 81Scraper on paving equipment. 82Cross section of PK piezo sensors . 85Installation of PK piezo sensors . 86Heating assembly for Kistler sensors . 89Grouting of the Kistler sensors . 92Finished WIM and wheel wander sensors . 94Truck setup for sensor calibration . 96Dynatest strain gauge response during roller pass . 99CTL strain gauge response during roller pass. 100Dynatest gauge producing noisy signal . 100CTL response to Marshall hammer drops . 103CTL response to FWD testing . 105Layout of pullboxes and conduits . 107Layout of conduits for pavement sensors . 109Installation of conduits for WIM, wheel wander sensors . 113Location of soil samples . 115Pavement coring . 117Sign bridge lift. 118Data transmission path. 121Database tables . 122Data viewer screen shot . 124xi

List of Figures (Cont.)Figure A-1Figure A-2Figure A-3Figure A-4Figure A-5Figure A-6Figure A-7Figure A-8Figure A-9Figure A-10Figure A-11Figure A-12Figure A-13Figure A-14Figure A-15Figure A-16Figure A-17Figure A-18Figure A-19Figure A-20Figure A-21Figure A-22Figure A-23Figure A-24Figure A-25CTL gauge I67/A0 .A-2CTL gauge I68/A1 .A-2CTL gauge I69/A2 .A-3CTL gauge I70/A3 .A-3CTL gauge I71/A4 .A-4CTL gauge I72/A5 .A-4CTL gauge I73/A6 .A-5CTL gauge I74/A7 .A-5CTL gauge I75/B0 .A-6CTL gauge I76/B1 .A-6CTL gauge I77/B2 .A-7CTL gauge I78/B3 .A-7CTL gauge I79/B4 .A-8CTL gauge I80/B5 .A-8CTL gauge I81/B6 .A-9CTL gauge I82/B7 .A-9CTL gauge I110/D5 .A-10Dynatest gauge 679-001/C0 .A-10Dynatest gauge 679-002/C1.A-11Dynatest gauge 679-003/C2 .A-11Dynatest gauge 679-004/C3 .A-12Dynatest gauge 679-005/C4 .A-12Dynatest gauge 679-006/C5 .A-13Dynatest gauge 679-007/C6 .A-13Dynatest gauge 679-008/C7.A-14List of TablesTable 2-1Table 2-2Table 3-1Table 3-2Table 3-3Table 4-1Table 4-2Table A-1Table A-2Equipment cost associated with WIM. 23Cost breakdown of other project equipment. 23Final locations of subgrade sensors. 63Correct resistance values for strain sensors . 102Conduit locations. 110Phase II work schedule . 128Phase II budget estimate . 128CTL strain sensor calibration factors.A-1Dynatest strain sensor calibration factors .A-1xii

Chapter 1 - Literature ReviewThis report has been submitted for fulfillment of task 5 in the original researchproposal submitted to the Wisconsin Highway Research Program for theMarquette Interchange Instrumentation Project. The report covers all of the workdone for this project covering preliminary literature review, field instrumentationplan, the procedures for installation of the individual instruments and systemcomponents, and finally the system demonstration.In fulfillment of Task 1 in the original proposal, a literature review of pastresearch in this particular area of study was conducted to help mold theinstrumentation and data acquisition plan. Review of past literature gave insightto what ideas have worked and provided the most valuable information. Theresearch may have been limited due to the current technology at the time orunforeseen troubles. Tailoring this research to the past also makes the newresearch somewhat comparable to the past. The two main researchprojects/programs that have been under scrutiny are the MnROAD study andNCAT test track.1.1 MnROAD Study(1 - 8)The MnROAD program was sponsored by the Minnesota Department ofTransportation and carried out by researchers at the University of Minnesota.The program involved studying both a test track for controlled loading and also aportion of Interstate 94 for loading under real conditions. The focus of the projectwas very broad and covered many aspects of pavement and highway design. Of1

interest to this research was the work done towards understanding the structuralresponse of different flexible pavements. Some outcomes of the project includedcalibrating pavement models to the local conditions in the region thus improvingthe accuracy of their pavement design procedures. The work done also helpedto shape a mechanistic-empirical design process.To measure the structural response of both PCC and HMA pavements,over 4,500 sensors were installed into the pavement structures. Of these 1,151of them were used to dynamically measure pavement response. Amongst thenumerous sensors were asphalt strain gauges and earth pressure cells. Thesetwo sensor types were the main resource for acquiring the dynamic loadresponse of the pavements. Many of the other sensors used were focusedprimarily for acquiring information regarding the environmental conditions andconditions for the supporting layers below the asphalt.The strain sensors were arranged in groups of three spanning across awheel-path. Some were placed to measure strain transversely to traffic whileothers were placed to measure longitudinally (in the direction of traffic), althoughno implications were given which orientation was used and why. Previous pilotstudies had been carried out but mainly focused on the type of instruments toutilize and not necessarily with the location and arrangement patterns.Optim Electronics MEGADAC data acquisition systems were used tocollect the data coming from the instruments. Acquisition was done at set timeintervals and not necessarily taken continuously.2

Researchers did note during the project that numerous sensors eventuallyfailed, crippling the effort. They also reported that they needed more dataconsisting of more axle configurations to use in creating and calibrating models.Work is ongoing at the MnROAD project site, but research regarding structuralresponse has subsided.1.2 NCAT(9 - 17)The National Center for Asphalt Technology (NCAT) at Auburn Universitytest track was started in 2000 and has continued today to be a source ofexcellent research concerning asphalt technology. The track consists of fortyfive flexible pavement test sections, each 200 feet long, and is constantly beingloaded by controlled semi-trucks. The trucks have been purchased for the solepurpose of applying load repetitions to the pavement and are driven on foreighteen hours a day, making the test track an accelerated performance testingfacility (consuming 10 to 15 years of design life in 2 years). Within the numeroustest sections are a huge variety of different research activities.In 2004 eight sections of the NCAT test track were devoted to installingsensors for measuring dynamic pavement responses. The eight sectionsselected were constructed of asphalt with varying structures and asphalt mixdesigns. Many CTL brand asphalt strain gauges were installed as the primarysource of data for pavement analysis. Along with these a handful of earthpressure cells (of two different types), vertical compression gauges, soil moisture3

(TDR) probes, and temperature probes were installed to provide supplemental,but important data.The installation of the sensors was a success with only a few gauges notsurviving installation. Low speed data was recorded for the environmentalsensors such as temperature and soil moisture. The strain sensors and earthpressure cells were recorded at high speed under trafficking from the calibratedtest vehicles. The data was analyzed in a piecewise manner; taking theinformation that was considered most crucial.The information taken from the study was used to calibrate the pavementdesign processes to the local variables. The stated objectives of this particularresearch were to validate mechanistic pavement models, develop transferfunctions for typical asphalt mixtures and pavement cross-sections, study thedynamic effects on pavement deterioration, and to evaluate the effect of layerthickness and polymer modification on structural performance.4

Chapter 2 - Field Instrumentation Plan2.1 Problem StatementThis pavement instrumentation plan was developed to provide pavementresponse data necessary for a detailed assessment of stress and strain inducedby traffic and environmental loadings and to provide information needed tovalidate fatigue models used for the design of long-life pavement systems.During the Spring/Summer of 2006, HMA perpetual pavements will be placedalong the North Leg of the Marquette Interchange reconstruction project. Thisproject offers a significant opportunity to examine the in-service performance of ahigh profile, highly-trafficked HMA perpetual pavement and has the potential toprovide benchmark performance data that can be used to validate pavementdesign models and help ensure the most cost-effective usage of pavementmaterials.The Marquette University Transportation Research Center (MU-TRC)research team has reviewed numerous published research reports andmanufacturers literature relevant to the design, installation, operation,maintenance and costs of pavement sensors and data collection/transmissionequipment. Research reports from the MnROAD study (1 - 8), the VirginiaSmartRoad (18) and the NCAT test track (9 - 17) provided significantcontributions to this study. Additional research papers presented at theTransportation Research Board and personal communications with variousauthors also provided significant input to this process. Construction plans for theNorth Leg pavements have been reviewed to identify opportunities/constraints for5

integrating pavement sensors and related recordation equipment into the definedproject limits. The results of these reviews have been synthesized into this planfor the instrumentation package that best satisfies project goals.2.2 Instrumentation LocationThe project plans for the North Leg pavements were reviewed in detail to identifypotential instrumentation locations. A number of meetings with the MarquetteInterchange construction team were also held to discuss the variousinstrumentation scenarios. A paramount concern for locating the instrumentationwas to identify a project location with minimal ramp conflicts or other pavementdesign details which might result in significant traffic wandering within theinstrumented lane. The selected location also needs to be in the vicinity of pullboxes located along the project length to ensure that conduit lines planned forinstallation as part of the interchange project would be available for use toprovide power and data transmission lines to the instrumentation location.A review of the project plans provided a number of possible locations,including the areas near Wisconsin Avenue, Brown Street and North Avenue.The Brown Street and North Avenue locations were identified as the twopreferred locations due to their proximity to planned pull boxes and existingcommunication vaults. The disadvantage of the Brown Street location, betweenstations 404 00 and 406 00, is the presence of an auxiliary lane which servesas the North Avenue exit ramp. This exit ramp may result in substantial trafficwandering within the zone of instrumentation.6

The North Avenue location, between stations 411 00 and 415 50,represents a standard 3-lane pavement section where minimal lane wandering isanticipated. This is the recommended installation location but there are somelimitations which bear noting. Between stations 411 00 and 413 00 the typicalproposed section includes a super elevated section with a surface cross-slope of5.10%, reducing to approximately 0.80% by station 415 00. The preferencewould be locate the instrumentation package in a section without signif

The outer wheel path of the outside lane was instrumented with asphalt strain sensors, base and subgrade pressure sensors, subgrade moisture and temperature sensors, HMA layer temperature sen